[syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod

[syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    25aa0bebba72 Merge tag 'net-6.5-rc6' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=169577fda80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2bf8962e4f7984f4
dashboard link: https://syzkaller.appspot.com/bug?extid=d66de4cbf532749df35f
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=148191c3a80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/76b0857d2814/disk-25aa0beb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a01574755257/vmlinux-25aa0beb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/262002db770e/bzImage-25aa0beb.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/b93cffaa6717/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d66de4cbf532749df35f@syzkaller.appspotmail.com

BUG: memory leak
unreferenced object 0xffff888129851240 (size 64):
  comm "syz-executor.0", pid 5069, jiffies 4294977377 (age 16.480s)
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff815545e5>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1076
    [<ffffffff821731b1>] kmalloc include/linux/slab.h:582 [inline]
    [<ffffffff821731b1>] btrfs_ref_tree_mod+0x211/0xb80 fs/btrfs/ref-verify.c:768
    [<ffffffff820444f6>] btrfs_free_tree_block+0x116/0x450 fs/btrfs/extent-tree.c:3250
    [<ffffffff8202d775>] __btrfs_cow_block+0x6a5/0xa30 fs/btrfs/ctree.c:601
    [<ffffffff8202dc54>] btrfs_cow_block+0x154/0x2b0 fs/btrfs/ctree.c:712
    [<ffffffff8206013c>] commit_cowonly_roots+0x8c/0x3f0 fs/btrfs/transaction.c:1276
    [<ffffffff820647c9>] btrfs_commit_transaction+0x999/0x15c0 fs/btrfs/transaction.c:2410
    [<ffffffff8205a516>] btrfs_commit_super+0x86/0xb0 fs/btrfs/disk-io.c:4195
    [<ffffffff8205c743>] close_ctree+0x543/0x730 fs/btrfs/disk-io.c:4349
    [<ffffffff8166b44e>] generic_shutdown_super+0x9e/0x1c0 fs/super.c:499
    [<ffffffff8166b769>] kill_anon_super+0x19/0x30 fs/super.c:1110
    [<ffffffff8202357d>] btrfs_kill_super+0x1d/0x30 fs/btrfs/super.c:2138
    [<ffffffff8166ca46>] deactivate_locked_super+0x46/0xd0 fs/super.c:330
    [<ffffffff8166cb6c>] deactivate_super fs/super.c:361 [inline]
    [<ffffffff8166cb6c>] deactivate_super+0x9c/0xb0 fs/super.c:357
    [<ffffffff816a8931>] cleanup_mnt+0x121/0x210 fs/namespace.c:1254
    [<ffffffff812becaf>] task_work_run+0x8f/0xe0 kernel/task_work.c:179



---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the bug is already fixed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to change bug's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the bug is a duplicate of another bug, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod
Author: bragathemanick0908@gmail.com


On 15/08/23 14:45, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    25aa0bebba72 Merge tag 'net-6.5-rc6' of git://git.kernel.o..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=169577fda80000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=2bf8962e4f7984f4
> dashboard link: https://syzkaller.appspot.com/bug?extid=d66de4cbf532749df35f
> compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=148191c3a80000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/76b0857d2814/disk-25aa0beb.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/a01574755257/vmlinux-25aa0beb.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/262002db770e/bzImage-25aa0beb.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/b93cffaa6717/mount_0.gz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+d66de4cbf532749df35f@syzkaller.appspotmail.com
>
> BUG: memory leak
> unreferenced object 0xffff888129851240 (size 64):
>    comm "syz-executor.0", pid 5069, jiffies 4294977377 (age 16.480s)
>    hex dump (first 32 bytes):
>      01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>    backtrace:
>      [<ffffffff815545e5>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1076
>      [<ffffffff821731b1>] kmalloc include/linux/slab.h:582 [inline]
>      [<ffffffff821731b1>] btrfs_ref_tree_mod+0x211/0xb80 fs/btrfs/ref-verify.c:768
>      [<ffffffff820444f6>] btrfs_free_tree_block+0x116/0x450 fs/btrfs/extent-tree.c:3250
>      [<ffffffff8202d775>] __btrfs_cow_block+0x6a5/0xa30 fs/btrfs/ctree.c:601
>      [<ffffffff8202dc54>] btrfs_cow_block+0x154/0x2b0 fs/btrfs/ctree.c:712
>      [<ffffffff8206013c>] commit_cowonly_roots+0x8c/0x3f0 fs/btrfs/transaction.c:1276
>      [<ffffffff820647c9>] btrfs_commit_transaction+0x999/0x15c0 fs/btrfs/transaction.c:2410
>      [<ffffffff8205a516>] btrfs_commit_super+0x86/0xb0 fs/btrfs/disk-io.c:4195
>      [<ffffffff8205c743>] close_ctree+0x543/0x730 fs/btrfs/disk-io.c:4349
>      [<ffffffff8166b44e>] generic_shutdown_super+0x9e/0x1c0 fs/super.c:499
>      [<ffffffff8166b769>] kill_anon_super+0x19/0x30 fs/super.c:1110
>      [<ffffffff8202357d>] btrfs_kill_super+0x1d/0x30 fs/btrfs/super.c:2138
>      [<ffffffff8166ca46>] deactivate_locked_super+0x46/0xd0 fs/super.c:330
>      [<ffffffff8166cb6c>] deactivate_super fs/super.c:361 [inline]
>      [<ffffffff8166cb6c>] deactivate_super+0x9c/0xb0 fs/super.c:357
>      [<ffffffff816a8931>] cleanup_mnt+0x121/0x210 fs/namespace.c:1254
>      [<ffffffff812becaf>] task_work_run+0x8f/0xe0 kernel/task_work.c:179
>
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the bug is already fixed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to change bug's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the bug is a duplicate of another bug, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
>
#syz test

diff --git a/fs/btrfs/ref-verify.c b/fs/btrfs/ref-verify.c
index 95d28497de7c..fbb24c65eeb0 100644
--- a/fs/btrfs/ref-verify.c
+++ b/fs/btrfs/ref-verify.c
@@ -791,6 +791,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
              dump_ref_action(fs_info, ra);
              kfree(ref);
              kfree(ra);
+            kfree(re);
              goto out_unlock;
          } else if (be->num_refs == 0) {
              btrfs_err(fs_info,
@@ -800,6 +801,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
              dump_ref_action(fs_info, ra);
              kfree(ref);
              kfree(ra);
+            kfree(re);
              goto out_unlock;
          }

@@ -822,6 +824,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
                  dump_ref_action(fs_info, ra);
                  kfree(ref);
                  kfree(ra);
+                kfree(re);
                  goto out_unlock;
              }
              exist->num_refs--;
@@ -838,6 +841,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
              dump_ref_action(fs_info, ra);
              kfree(ref);
              kfree(ra);
+            kfree(re);
              goto out_unlock;
          }
          kfree(ref);
@@ -849,6 +853,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
              dump_ref_action(fs_info, ra);
              kfree(ref);
              kfree(ra);
+            kfree(re);
              goto out_unlock;
          }
      }
@@ -881,6 +886,8 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
      }
      list_add_tail(&ra->list, &be->actions);
      ret = 0;
+    kfree(ra);
+    kfree(re);
  out_unlock:
      spin_unlock(&fs_info->ref_verify_lock);
  out:

Re: [syzbot] Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod
Author: bragathemanick0908@gmail.com


On 12/11/23 14:53, syzbot wrote:
> Hello,
>
> syzbot tried to test the proposed patch but the build/boot failed:
>
> failed to apply patch:
> checking file fs/btrfs/ref-verify.c
> Hunk #1 FAILED at 791.
> Hunk #2 FAILED at 800.
> 2 out of 2 hunks FAILED
>
>
>
> Tested on:
>
> commit:         1b907d05 Merge tag '6.7-rc-smb3-client-fixes-part2' of..
> git tree:       upstream
> kernel config:  https://syzkaller.appspot.com/x/.config?x=2bf8962e4f7984f4
> dashboard link: https://syzkaller.appspot.com/bug?extid=d66de4cbf532749df35f
> compiler:
> patch:          https://syzkaller.appspot.com/x/patch.diff?x=16845fe0e80000
>
#syz test

--- a/fs/btrfs/ref-verify.c
+++ b/fs/btrfs/ref-verify.c
@@ -791,6 +791,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
              dump_ref_action(fs_info, ra);
              kfree(ref);
              kfree(ra);
+            kfree(re);
              goto out_unlock;
          } else if (be->num_refs == 0) {
              btrfs_err(fs_info,
@@ -800,6 +801,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
              dump_ref_action(fs_info, ra);
              kfree(ref);
              kfree(ra);
+            kfree(re);
              goto out_unlock;
          }

@@ -822,6 +824,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
                  dump_ref_action(fs_info, ra);
                  kfree(ref);
                  kfree(ra);
+                kfree(re);
                  goto out_unlock;
              }
              exist->num_refs--;
@@ -838,6 +841,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
              dump_ref_action(fs_info, ra);
              kfree(ref);
              kfree(ra);
+            kfree(re);
              goto out_unlock;
          }
          kfree(ref);
@@ -849,6 +853,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
              dump_ref_action(fs_info, ra);
              kfree(ref);
              kfree(ra);
+            kfree(re);
              goto out_unlock;
          }
      }
@@ -881,6 +886,8 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
      }
      list_add_tail(&ra->list, &be->actions);
      ret = 0;
+    kfree(ra);
+    kfree(re);
  out_unlock:
      spin_unlock(&fs_info->ref_verify_lock);
  out:

Re: [syzbot] Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod
Author: bragathemanick0908@gmail.com

#syz test 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 
25aa0bebba72

--- a/fs/btrfs/ref-verify.c
+++ b/fs/btrfs/ref-verify.c
@@ -791,6 +791,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
              dump_ref_action(fs_info, ra);
              kfree(ref);
              kfree(ra);
+            kfree(re);
              goto out_unlock;
          } else if (be->num_refs == 0) {
              btrfs_err(fs_info,
@@ -800,6 +801,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
              dump_ref_action(fs_info, ra);
              kfree(ref);
              kfree(ra);
+            kfree(re);
              goto out_unlock;
          }
@@ -822,6 +824,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
                  dump_ref_action(fs_info, ra);
                  kfree(ref);
                  kfree(ra);
+                kfree(re);
                  goto out_unlock;
              }
              exist->num_refs--;
@@ -838,6 +841,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
              dump_ref_action(fs_info, ra);
              kfree(ref);
              kfree(ra);
+            kfree(re);
              goto out_unlock;
          }
          kfree(ref);
@@ -849,6 +853,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
              dump_ref_action(fs_info, ra);
              kfree(ref);
              kfree(ra);
+            kfree(re);
              goto out_unlock;
          }
      }
@@ -881,6 +886,8 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
      }
      list_add_tail(&ra->list, &be->actions);
      ret = 0;
+    kfree(ra);
+    kfree(re);
  out_unlock:
      spin_unlock(&fs_info->ref_verify_lock);
  out:

Re: [syzbot] Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod
Author: bragathemanick0908@gmail.com

#syz test: 
git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 
25aa0bebba72b318e71fe205bfd1236550cc9534

On 15/08/23 14:45, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    25aa0bebba72 Merge tag 'net-6.5-rc6' of git://git.kernel.o..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=169577fda80000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=2bf8962e4f7984f4
> dashboard link: https://syzkaller.appspot.com/bug?extid=d66de4cbf532749df35f
> compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=148191c3a80000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/76b0857d2814/disk-25aa0beb.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/a01574755257/vmlinux-25aa0beb.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/262002db770e/bzImage-25aa0beb.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/b93cffaa6717/mount_0.gz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+d66de4cbf532749df35f@syzkaller.appspotmail.com
>
> BUG: memory leak
> unreferenced object 0xffff888129851240 (size 64):
>    comm "syz-executor.0", pid 5069, jiffies 4294977377 (age 16.480s)
>    hex dump (first 32 bytes):
>      01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>    backtrace:
>      [<ffffffff815545e5>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1076
>      [<ffffffff821731b1>] kmalloc include/linux/slab.h:582 [inline]
>      [<ffffffff821731b1>] btrfs_ref_tree_mod+0x211/0xb80 fs/btrfs/ref-verify.c:768
>      [<ffffffff820444f6>] btrfs_free_tree_block+0x116/0x450 fs/btrfs/extent-tree.c:3250
>      [<ffffffff8202d775>] __btrfs_cow_block+0x6a5/0xa30 fs/btrfs/ctree.c:601
>      [<ffffffff8202dc54>] btrfs_cow_block+0x154/0x2b0 fs/btrfs/ctree.c:712
>      [<ffffffff8206013c>] commit_cowonly_roots+0x8c/0x3f0 fs/btrfs/transaction.c:1276
>      [<ffffffff820647c9>] btrfs_commit_transaction+0x999/0x15c0 fs/btrfs/transaction.c:2410
>      [<ffffffff8205a516>] btrfs_commit_super+0x86/0xb0 fs/btrfs/disk-io.c:4195
>      [<ffffffff8205c743>] close_ctree+0x543/0x730 fs/btrfs/disk-io.c:4349
>      [<ffffffff8166b44e>] generic_shutdown_super+0x9e/0x1c0 fs/super.c:499
>      [<ffffffff8166b769>] kill_anon_super+0x19/0x30 fs/super.c:1110
>      [<ffffffff8202357d>] btrfs_kill_super+0x1d/0x30 fs/btrfs/super.c:2138
>      [<ffffffff8166ca46>] deactivate_locked_super+0x46/0xd0 fs/super.c:330
>      [<ffffffff8166cb6c>] deactivate_super fs/super.c:361 [inline]
>      [<ffffffff8166cb6c>] deactivate_super+0x9c/0xb0 fs/super.c:357
>      [<ffffffff816a8931>] cleanup_mnt+0x121/0x210 fs/namespace.c:1254
>      [<ffffffff812becaf>] task_work_run+0x8f/0xe0 kernel/task_work.c:179
>
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the bug is already fixed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to change bug's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the bug is a duplicate of another bug, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
>

Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod

[Bragatheswaran Manickavel]

[-- Attachment #1: Type: text/plain, Size: 3906 bytes --]

#syz test: 
git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 
25aa0bebba72b318e71fe205bfd1236550cc9534

On 15/08/23 14:45, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    25aa0bebba72 Merge tag 'net-6.5-rc6' of git://git.kernel.o..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=169577fda80000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=2bf8962e4f7984f4
> dashboard link: https://syzkaller.appspot.com/bug?extid=d66de4cbf532749df35f
> compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=148191c3a80000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/76b0857d2814/disk-25aa0beb.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/a01574755257/vmlinux-25aa0beb.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/262002db770e/bzImage-25aa0beb.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/b93cffaa6717/mount_0.gz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+d66de4cbf532749df35f@syzkaller.appspotmail.com
>
> BUG: memory leak
> unreferenced object 0xffff888129851240 (size 64):
>    comm "syz-executor.0", pid 5069, jiffies 4294977377 (age 16.480s)
>    hex dump (first 32 bytes):
>      01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>    backtrace:
>      [<ffffffff815545e5>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1076
>      [<ffffffff821731b1>] kmalloc include/linux/slab.h:582 [inline]
>      [<ffffffff821731b1>] btrfs_ref_tree_mod+0x211/0xb80 fs/btrfs/ref-verify.c:768
>      [<ffffffff820444f6>] btrfs_free_tree_block+0x116/0x450 fs/btrfs/extent-tree.c:3250
>      [<ffffffff8202d775>] __btrfs_cow_block+0x6a5/0xa30 fs/btrfs/ctree.c:601
>      [<ffffffff8202dc54>] btrfs_cow_block+0x154/0x2b0 fs/btrfs/ctree.c:712
>      [<ffffffff8206013c>] commit_cowonly_roots+0x8c/0x3f0 fs/btrfs/transaction.c:1276
>      [<ffffffff820647c9>] btrfs_commit_transaction+0x999/0x15c0 fs/btrfs/transaction.c:2410
>      [<ffffffff8205a516>] btrfs_commit_super+0x86/0xb0 fs/btrfs/disk-io.c:4195
>      [<ffffffff8205c743>] close_ctree+0x543/0x730 fs/btrfs/disk-io.c:4349
>      [<ffffffff8166b44e>] generic_shutdown_super+0x9e/0x1c0 fs/super.c:499
>      [<ffffffff8166b769>] kill_anon_super+0x19/0x30 fs/super.c:1110
>      [<ffffffff8202357d>] btrfs_kill_super+0x1d/0x30 fs/btrfs/super.c:2138
>      [<ffffffff8166ca46>] deactivate_locked_super+0x46/0xd0 fs/super.c:330
>      [<ffffffff8166cb6c>] deactivate_super fs/super.c:361 [inline]
>      [<ffffffff8166cb6c>] deactivate_super+0x9c/0xb0 fs/super.c:357
>      [<ffffffff816a8931>] cleanup_mnt+0x121/0x210 fs/namespace.c:1254
>      [<ffffffff812becaf>] task_work_run+0x8f/0xe0 kernel/task_work.c:179
>
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the bug is already fixed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to change bug's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the bug is a duplicate of another bug, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
>

[-- Attachment #2: btrfs.diff --]
[-- Type: text/x-patch, Size: 1158 bytes --]

diff --git a/fs/btrfs/ref-verify.c b/fs/btrfs/ref-verify.c
index 95d28497de7c..50b59b3dc474 100644
--- a/fs/btrfs/ref-verify.c
+++ b/fs/btrfs/ref-verify.c
@@ -791,6 +791,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
 			dump_ref_action(fs_info, ra);
 			kfree(ref);
 			kfree(ra);
+			kfree(re);
 			goto out_unlock;
 		} else if (be->num_refs == 0) {
 			btrfs_err(fs_info,
@@ -800,6 +801,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
 			dump_ref_action(fs_info, ra);
 			kfree(ref);
 			kfree(ra);
+			kfree(re);
 			goto out_unlock;
 		}
 
@@ -822,6 +824,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
 				dump_ref_action(fs_info, ra);
 				kfree(ref);
 				kfree(ra);
+				kfree(re);
 				goto out_unlock;
 			}
 			exist->num_refs--;
@@ -838,6 +841,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
 			dump_ref_action(fs_info, ra);
 			kfree(ref);
 			kfree(ra);
+			kfree(re);
 			goto out_unlock;
 		}
 		kfree(ref);
@@ -849,6 +853,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
 			dump_ref_action(fs_info, ra);
 			kfree(ref);
 			kfree(ra);
+			kfree(re);
 			goto out_unlock;
 		}
 	}

Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+d66de4cbf532749df35f@syzkaller.appspotmail.com

Tested on:

commit:         25aa0beb Merge tag 'net-6.5-rc6' of git://git.kernel.o..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=17c578a8e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2bf8962e4f7984f4
dashboard link: https://syzkaller.appspot.com/bug?extid=d66de4cbf532749df35f
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=16ce93e0e80000

Note: testing is done by a robot and is best-effort only.

Re: [syzbot] memory leak in btrfs_ref_tree_mod

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: memory leak in btrfs_ref_tree_mod
Author: jose.pekkarinen@foxhound.fi


#syz test: 
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 
5a6a09e97199d6600d31383055f9d43fbbcbe86f

     José Pekkarinen.

Re: [syzbot] Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod
Author: bragathemanick0908@gmail.com

#syz test: 
git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 
25aa0bebba72b318e71fe205bfd1236550cc9534

On 15/08/23 14:45, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    25aa0bebba72 Merge tag 'net-6.5-rc6' of git://git.kernel.o..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=169577fda80000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=2bf8962e4f7984f4
> dashboard link: https://syzkaller.appspot.com/bug?extid=d66de4cbf532749df35f
> compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=148191c3a80000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/76b0857d2814/disk-25aa0beb.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/a01574755257/vmlinux-25aa0beb.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/262002db770e/bzImage-25aa0beb.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/b93cffaa6717/mount_0.gz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+d66de4cbf532749df35f@syzkaller.appspotmail.com
>
> BUG: memory leak
> unreferenced object 0xffff888129851240 (size 64):
>    comm "syz-executor.0", pid 5069, jiffies 4294977377 (age 16.480s)
>    hex dump (first 32 bytes):
>      01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>    backtrace:
>      [<ffffffff815545e5>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1076
>      [<ffffffff821731b1>] kmalloc include/linux/slab.h:582 [inline]
>      [<ffffffff821731b1>] btrfs_ref_tree_mod+0x211/0xb80 fs/btrfs/ref-verify.c:768
>      [<ffffffff820444f6>] btrfs_free_tree_block+0x116/0x450 fs/btrfs/extent-tree.c:3250
>      [<ffffffff8202d775>] __btrfs_cow_block+0x6a5/0xa30 fs/btrfs/ctree.c:601
>      [<ffffffff8202dc54>] btrfs_cow_block+0x154/0x2b0 fs/btrfs/ctree.c:712
>      [<ffffffff8206013c>] commit_cowonly_roots+0x8c/0x3f0 fs/btrfs/transaction.c:1276
>      [<ffffffff820647c9>] btrfs_commit_transaction+0x999/0x15c0 fs/btrfs/transaction.c:2410
>      [<ffffffff8205a516>] btrfs_commit_super+0x86/0xb0 fs/btrfs/disk-io.c:4195
>      [<ffffffff8205c743>] close_ctree+0x543/0x730 fs/btrfs/disk-io.c:4349
>      [<ffffffff8166b44e>] generic_shutdown_super+0x9e/0x1c0 fs/super.c:499
>      [<ffffffff8166b769>] kill_anon_super+0x19/0x30 fs/super.c:1110
>      [<ffffffff8202357d>] btrfs_kill_super+0x1d/0x30 fs/btrfs/super.c:2138
>      [<ffffffff8166ca46>] deactivate_locked_super+0x46/0xd0 fs/super.c:330
>      [<ffffffff8166cb6c>] deactivate_super fs/super.c:361 [inline]
>      [<ffffffff8166cb6c>] deactivate_super+0x9c/0xb0 fs/super.c:357
>      [<ffffffff816a8931>] cleanup_mnt+0x121/0x210 fs/namespace.c:1254
>      [<ffffffff812becaf>] task_work_run+0x8f/0xe0 kernel/task_work.c:179
>
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the bug is already fixed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to change bug's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the bug is a duplicate of another bug, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
>

Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to apply patch:
checking file fs/btrfs/ref-verify.c
Hunk #1 FAILED at 791.
Hunk #2 FAILED at 800.
2 out of 2 hunks FAILED



Tested on:

commit:         1b907d05 Merge tag '6.7-rc-smb3-client-fixes-part2' of..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=2bf8962e4f7984f4
dashboard link: https://syzkaller.appspot.com/bug?extid=d66de4cbf532749df35f
compiler:       
patch:          https://syzkaller.appspot.com/x/patch.diff?x=16845fe0e80000

Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to apply patch:
checking file fs/btrfs/ref-verify.c
Hunk #1 FAILED at 791.
Hunk #2 FAILED at 800.
2 out of 2 hunks FAILED



Tested on:

commit:         1b907d05 Merge tag '6.7-rc-smb3-client-fixes-part2' of..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=2bf8962e4f7984f4
dashboard link: https://syzkaller.appspot.com/bug?extid=d66de4cbf532749df35f
compiler:       
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1652c75b680000

Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to apply patch:
checking file fs/btrfs/ref-verify.c
Hunk #1 FAILED at 791.
patch: **** malformed patch at line 18: @@ -822,6 +824,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,




Tested on:

commit:         1b907d05 Merge tag '6.7-rc-smb3-client-fixes-part2' of..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=2bf8962e4f7984f4
dashboard link: https://syzkaller.appspot.com/bug?extid=d66de4cbf532749df35f
compiler:       
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15e11eff680000

Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
BUG: corrupted list in btrfs_ref_tree_mod

list_add corruption. prev->next should be next (ffff888122a51108), but was 0000000000058000. (prev=ffff88810e236d50).
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:30!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU: 0 PID: 45 Comm: kworker/u4:2 Not tainted 6.5.0-rc5-syzkaller-00182-g25aa0bebba72-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Workqueue: btrfs-qgroup-rescan btrfs_work_helper
RIP: 0010:__list_add_valid+0x74/0x90 lib/list_debug.c:30
Code: e2 fe 0f 0b 48 89 c1 48 c7 c7 68 ff af 85 e8 a3 d7 e2 fe 0f 0b 48 89 d1 48 89 c6 4c 89 c2 48 c7 c7 c0 ff af 85 e8 8c d7 e2 fe <0f> 0b 48 89 f2 48 89 c1 48 89 fe 48 c7 c7 18 00 b0 85 e8 75 d7 e2
RSP: 0018:ffffc900001cf920 EFLAGS: 00010246
RAX: 0000000000000075 RBX: ffff88810e236d50 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8131cbd0 RDI: 0000000000000001
RBP: ffff888122a51108 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 205d353454202020 R12: 0000000000000000
R13: ffff888122aec700 R14: ffff888122aec750 R15: ffff888122a510c0
FS:  0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd2648f75e8 CR3: 000000010a57a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __list_add include/linux/list.h:69 [inline]
 list_add_tail include/linux/list.h:102 [inline]
 btrfs_ref_tree_mod+0x454/0xbb0 fs/btrfs/ref-verify.c:887
 btrfs_free_tree_block+0x116/0x450 fs/btrfs/extent-tree.c:3250
 __btrfs_cow_block+0x6a5/0xa30 fs/btrfs/ctree.c:601
 btrfs_cow_block+0x154/0x2b0 fs/btrfs/ctree.c:712
 btrfs_search_slot+0xa49/0x1770 fs/btrfs/ctree.c:2194
 btrfs_update_root+0x6f/0x500 fs/btrfs/root-tree.c:137
 commit_fs_roots+0x236/0x360 fs/btrfs/transaction.c:1450
 btrfs_commit_transaction+0x93e/0x15c0 fs/btrfs/transaction.c:2393
 btrfs_qgroup_rescan_worker+0x389/0x610 fs/btrfs/qgroup.c:3417
 btrfs_work_helper+0x158/0x540 fs/btrfs/async-thread.c:314
 process_one_work+0x2f1/0x640 kernel/workqueue.c:2600
 worker_thread+0x5c/0x5c0 kernel/workqueue.c:2751
 kthread+0x12b/0x170 kernel/kthread.c:389
 ret_from_fork+0x2c/0x40 arch/x86/kernel/process.c:145
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_add_valid+0x74/0x90 lib/list_debug.c:30
Code: e2 fe 0f 0b 48 89 c1 48 c7 c7 68 ff af 85 e8 a3 d7 e2 fe 0f 0b 48 89 d1 48 89 c6 4c 89 c2 48 c7 c7 c0 ff af 85 e8 8c d7 e2 fe <0f> 0b 48 89 f2 48 89 c1 48 89 fe 48 c7 c7 18 00 b0 85 e8 75 d7 e2
RSP: 0018:ffffc900001cf920 EFLAGS: 00010246

RAX: 0000000000000075 RBX: ffff88810e236d50 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8131cbd0 RDI: 0000000000000001
RBP: ffff888122a51108 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 205d353454202020 R12: 0000000000000000
R13: ffff888122aec700 R14: ffff888122aec750 R15: ffff888122a510c0
FS:  0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd2648f75e8 CR3: 000000010a57a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


Tested on:

commit:         25aa0beb Merge tag 'net-6.5-rc6' of git://git.kernel.o..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=10deb938e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2bf8962e4f7984f4
dashboard link: https://syzkaller.appspot.com/bug?extid=d66de4cbf532749df35f
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=16a72ca7680000

Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
memory leak in add_block_entry

BUG: memory leak
unreferenced object 0xffff888122f9fe40 (size 64):
  comm "syz-executor.1", pid 5844, jiffies 4294945528 (age 11.970s)
  hex dump (first 32 bytes):
    03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff81578015>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1098
    [<ffffffff821ae165>] kmalloc include/linux/slab.h:600 [inline]
    [<ffffffff821ae165>] kzalloc include/linux/slab.h:721 [inline]
    [<ffffffff821ae165>] add_block_entry+0x35/0x320 fs/btrfs/ref-verify.c:270
    [<ffffffff821ae806>] add_tree_block+0x96/0x240 fs/btrfs/ref-verify.c:332
    [<ffffffff821afdf6>] process_extent_item fs/btrfs/ref-verify.c:474 [inline]
    [<ffffffff821afdf6>] process_leaf fs/btrfs/ref-verify.c:524 [inline]
    [<ffffffff821afdf6>] walk_down_tree fs/btrfs/ref-verify.c:576 [inline]
    [<ffffffff821afdf6>] btrfs_build_ref_tree+0x566/0x8c0 fs/btrfs/ref-verify.c:1013
    [<ffffffff82095365>] open_ctree+0x18c5/0x2370 fs/btrfs/disk-io.c:3523
    [<ffffffff8205ab21>] btrfs_fill_super fs/btrfs/super.c:1117 [inline]
    [<ffffffff8205ab21>] btrfs_mount_root+0x5a1/0x750 fs/btrfs/super.c:1478
    [<ffffffff816fd5a9>] legacy_get_tree+0x29/0x80 fs/fs_context.c:662
    [<ffffffff81692d2a>] vfs_get_tree+0x2a/0x130 fs/super.c:1768
    [<ffffffff816d06db>] fc_mount fs/namespace.c:1114 [inline]
    [<ffffffff816d06db>] vfs_kern_mount.part.0+0xcb/0x110 fs/namespace.c:1144
    [<ffffffff816d075f>] vfs_kern_mount+0x3f/0x60 fs/namespace.c:1131
    [<ffffffff8205eb82>] btrfs_mount+0x1e2/0x660 fs/btrfs/super.c:1538
    [<ffffffff816fd5a9>] legacy_get_tree+0x29/0x80 fs/fs_context.c:662
    [<ffffffff81692d2a>] vfs_get_tree+0x2a/0x130 fs/super.c:1768
    [<ffffffff816d882f>] do_new_mount fs/namespace.c:3337 [inline]
    [<ffffffff816d882f>] path_mount+0xc8f/0x10d0 fs/namespace.c:3664
    [<ffffffff816d9421>] do_mount fs/namespace.c:3677 [inline]
    [<ffffffff816d9421>] __do_sys_mount fs/namespace.c:3886 [inline]
    [<ffffffff816d9421>] __se_sys_mount fs/namespace.c:3863 [inline]
    [<ffffffff816d9421>] __x64_sys_mount+0x1a1/0x1f0 fs/namespace.c:3863
    [<ffffffff84b4945f>] do_syscall_x64 arch/x86/entry/common.c:51 [inline]
    [<ffffffff84b4945f>] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82

BUG: memory leak
unreferenced object 0xffff8881216a7ba0 (size 96):
  comm "syz-executor.1", pid 5844, jiffies 4294945528 (age 11.970s)
  hex dump (first 32 bytes):
    00 10 10 00 00 00 00 00 00 10 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 01 00 00 00 01 00 00 00  ................
  backtrace:
    [<ffffffff81578015>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1098
    [<ffffffff821ae17e>] kmalloc include/linux/slab.h:600 [inline]
    [<ffffffff821ae17e>] kzalloc include/linux/slab.h:721 [inline]
    [<ffffffff821ae17e>] add_block_entry+0x4e/0x320 fs/btrfs/ref-verify.c:271
    [<ffffffff821ae806>] add_tree_block+0x96/0x240 fs/btrfs/ref-verify.c:332
    [<ffffffff821afdf6>] process_extent_item fs/btrfs/ref-verify.c:474 [inline]
    [<ffffffff821afdf6>] process_leaf fs/btrfs/ref-verify.c:524 [inline]
    [<ffffffff821afdf6>] walk_down_tree fs/btrfs/ref-verify.c:576 [inline]
    [<ffffffff821afdf6>] btrfs_build_ref_tree+0x566/0x8c0 fs/btrfs/ref-verify.c:1013
    [<ffffffff82095365>] open_ctree+0x18c5/0x2370 fs/btrfs/disk-io.c:3523
    [<ffffffff8205ab21>] btrfs_fill_super fs/btrfs/super.c:1117 [inline]
    [<ffffffff8205ab21>] btrfs_mount_root+0x5a1/0x750 fs/btrfs/super.c:1478
    [<ffffffff816fd5a9>] legacy_get_tree+0x29/0x80 fs/fs_context.c:662
    [<ffffffff81692d2a>] vfs_get_tree+0x2a/0x130 fs/super.c:1768
    [<ffffffff816d06db>] fc_mount fs/namespace.c:1114 [inline]
    [<ffffffff816d06db>] vfs_kern_mount.part.0+0xcb/0x110 fs/namespace.c:1144
    [<ffffffff816d075f>] vfs_kern_mount+0x3f/0x60 fs/namespace.c:1131
    [<ffffffff8205eb82>] btrfs_mount+0x1e2/0x660 fs/btrfs/super.c:1538
    [<ffffffff816fd5a9>] legacy_get_tree+0x29/0x80 fs/fs_context.c:662
    [<ffffffff81692d2a>] vfs_get_tree+0x2a/0x130 fs/super.c:1768
    [<ffffffff816d882f>] do_new_mount fs/namespace.c:3337 [inline]
    [<ffffffff816d882f>] path_mount+0xc8f/0x10d0 fs/namespace.c:3664
    [<ffffffff816d9421>] do_mount fs/namespace.c:3677 [inline]
    [<ffffffff816d9421>] __do_sys_mount fs/namespace.c:3886 [inline]
    [<ffffffff816d9421>] __se_sys_mount fs/namespace.c:3863 [inline]
    [<ffffffff816d9421>] __x64_sys_mount+0x1a1/0x1f0 fs/namespace.c:3863
    [<ffffffff84b4945f>] do_syscall_x64 arch/x86/entry/common.c:51 [inline]
    [<ffffffff84b4945f>] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82

BUG: memory leak
unreferenced object 0xffff888122f9fec0 (size 64):
  comm "syz-executor.1", pid 5844, jiffies 4294945528 (age 11.970s)
  hex dump (first 32 bytes):
    05 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff81578015>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1098
    [<ffffffff821ae165>] kmalloc include/linux/slab.h:600 [inline]
    [<ffffffff821ae165>] kzalloc include/linux/slab.h:721 [inline]
    [<ffffffff821ae165>] add_block_entry+0x35/0x320 fs/btrfs/ref-verify.c:270
    [<ffffffff821ae806>] add_tree_block+0x96/0x240 fs/btrfs/ref-verify.c:332
    [<ffffffff821afdf6>] process_extent_item fs/btrfs/ref-verify.c:474 [inline]
    [<ffffffff821afdf6>] process_leaf fs/btrfs/ref-verify.c:524 [inline]
    [<ffffffff821afdf6>] walk_down_tree fs/btrfs/ref-verify.c:576 [inline]
    [<ffffffff821afdf6>] btrfs_build_ref_tree+0x566/0x8c0 fs/btrfs/ref-verify.c:1013
    [<ffffffff82095365>] open_ctree+0x18c5/0x2370 fs/btrfs/disk-io.c:3523
    [<ffffffff8205ab21>] btrfs_fill_super fs/btrfs/super.c:1117 [inline]
    [<ffffffff8205ab21>] btrfs_mount_root+0x5a1/0x750 fs/btrfs/super.c:1478
    [<ffffffff816fd5a9>] legacy_get_tree+0x29/0x80 fs/fs_context.c:662
    [<ffffffff81692d2a>] vfs_get_tree+0x2a/0x130 fs/super.c:1768
    [<ffffffff816d06db>] fc_mount fs/namespace.c:1114 [inline]
    [<ffffffff816d06db>] vfs_kern_mount.part.0+0xcb/0x110 fs/namespace.c:1144
    [<ffffffff816d075f>] vfs_kern_mount+0x3f/0x60 fs/namespace.c:1131
    [<ffffffff8205eb82>] btrfs_mount+0x1e2/0x660 fs/btrfs/super.c:1538
    [<ffffffff816fd5a9>] legacy_get_tree+0x29/0x80 fs/fs_context.c:662
    [<ffffffff81692d2a>] vfs_get_tree+0x2a/0x130 fs/super.c:1768
    [<ffffffff816d882f>] do_new_mount fs/namespace.c:3337 [inline]
    [<ffffffff816d882f>] path_mount+0xc8f/0x10d0 fs/namespace.c:3664
    [<ffffffff816d9421>] do_mount fs/namespace.c:3677 [inline]
    [<ffffffff816d9421>] __do_sys_mount fs/namespace.c:3886 [inline]
    [<ffffffff816d9421>] __se_sys_mount fs/namespace.c:3863 [inline]
    [<ffffffff816d9421>] __x64_sys_mount+0x1a1/0x1f0 fs/namespace.c:3863
    [<ffffffff84b4945f>] do_syscall_x64 arch/x86/entry/common.c:51 [inline]
    [<ffffffff84b4945f>] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82



Tested on:

commit:         5a6a09e9 Merge tag 'cgroup-for-6.7' of git://git.kerne..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=12ab8f5b680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=492c9379bc08e464
dashboard link: https://syzkaller.appspot.com/bug?extid=d66de4cbf532749df35f
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=17406848e80000

Re: [syzbot] [btrfs?] memory leak in btrfs_ref_tree_mod

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
memory leak in add_tree_block

BUG: memory leak
unreferenced object 0xffff88812611f380 (size 64):
  comm "syz-executor.5", pid 7474, jiffies 4294960257 (age 171.960s)
  hex dump (first 32 bytes):
    03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff815545e5>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1076
    [<ffffffff82172d99>] kmalloc include/linux/slab.h:582 [inline]
    [<ffffffff82172d99>] add_tree_block+0x39/0x240 fs/btrfs/ref-verify.c:319
    [<ffffffff821743f9>] process_extent_item fs/btrfs/ref-verify.c:474 [inline]
    [<ffffffff821743f9>] process_leaf fs/btrfs/ref-verify.c:521 [inline]
    [<ffffffff821743f9>] walk_down_tree fs/btrfs/ref-verify.c:573 [inline]
    [<ffffffff821743f9>] btrfs_build_ref_tree+0x589/0x850 fs/btrfs/ref-verify.c:1008
    [<ffffffff8205ec90>] open_ctree+0x1890/0x2270 fs/btrfs/disk-io.c:3471
    [<ffffffff8202582f>] btrfs_fill_super fs/btrfs/super.c:1154 [inline]
    [<ffffffff8202582f>] btrfs_mount_root+0x5af/0x750 fs/btrfs/super.c:1519
    [<ffffffff816d3e39>] legacy_get_tree+0x29/0x80 fs/fs_context.c:611
    [<ffffffff8166b7ea>] vfs_get_tree+0x2a/0x110 fs/super.c:1519
    [<ffffffff816a776b>] fc_mount fs/namespace.c:1112 [inline]
    [<ffffffff816a776b>] vfs_kern_mount.part.0+0xcb/0x110 fs/namespace.c:1142
    [<ffffffff816a77ef>] vfs_kern_mount+0x3f/0x60 fs/namespace.c:1129
    [<ffffffff820298b2>] btrfs_mount+0x1e2/0x660 fs/btrfs/super.c:1579
    [<ffffffff816d3e39>] legacy_get_tree+0x29/0x80 fs/fs_context.c:611
    [<ffffffff8166b7ea>] vfs_get_tree+0x2a/0x110 fs/super.c:1519
    [<ffffffff816afcff>] do_new_mount fs/namespace.c:3335 [inline]
    [<ffffffff816afcff>] path_mount+0xc8f/0x10d0 fs/namespace.c:3662
    [<ffffffff816b08f1>] do_mount fs/namespace.c:3675 [inline]
    [<ffffffff816b08f1>] __do_sys_mount fs/namespace.c:3884 [inline]
    [<ffffffff816b08f1>] __se_sys_mount fs/namespace.c:3861 [inline]
    [<ffffffff816b08f1>] __x64_sys_mount+0x1a1/0x1f0 fs/namespace.c:3861
    [<ffffffff84ad2bb8>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff84ad2bb8>] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
    [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

BUG: memory leak
unreferenced object 0xffff88812611f500 (size 64):
  comm "syz-executor.5", pid 7474, jiffies 4294960257 (age 171.960s)
  hex dump (first 32 bytes):
    03 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00  ................
    01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff815545e5>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1076
    [<ffffffff82172755>] kmalloc include/linux/slab.h:582 [inline]
    [<ffffffff82172755>] kzalloc include/linux/slab.h:703 [inline]
    [<ffffffff82172755>] add_block_entry+0x35/0x320 fs/btrfs/ref-verify.c:270
    [<ffffffff82172df6>] add_tree_block+0x96/0x240 fs/btrfs/ref-verify.c:332
    [<ffffffff821743f9>] process_extent_item fs/btrfs/ref-verify.c:474 [inline]
    [<ffffffff821743f9>] process_leaf fs/btrfs/ref-verify.c:521 [inline]
    [<ffffffff821743f9>] walk_down_tree fs/btrfs/ref-verify.c:573 [inline]
    [<ffffffff821743f9>] btrfs_build_ref_tree+0x589/0x850 fs/btrfs/ref-verify.c:1008
    [<ffffffff8205ec90>] open_ctree+0x1890/0x2270 fs/btrfs/disk-io.c:3471
    [<ffffffff8202582f>] btrfs_fill_super fs/btrfs/super.c:1154 [inline]
    [<ffffffff8202582f>] btrfs_mount_root+0x5af/0x750 fs/btrfs/super.c:1519
    [<ffffffff816d3e39>] legacy_get_tree+0x29/0x80 fs/fs_context.c:611
    [<ffffffff8166b7ea>] vfs_get_tree+0x2a/0x110 fs/super.c:1519
    [<ffffffff816a776b>] fc_mount fs/namespace.c:1112 [inline]
    [<ffffffff816a776b>] vfs_kern_mount.part.0+0xcb/0x110 fs/namespace.c:1142
    [<ffffffff816a77ef>] vfs_kern_mount+0x3f/0x60 fs/namespace.c:1129
    [<ffffffff820298b2>] btrfs_mount+0x1e2/0x660 fs/btrfs/super.c:1579
    [<ffffffff816d3e39>] legacy_get_tree+0x29/0x80 fs/fs_context.c:611
    [<ffffffff8166b7ea>] vfs_get_tree+0x2a/0x110 fs/super.c:1519
    [<ffffffff816afcff>] do_new_mount fs/namespace.c:3335 [inline]
    [<ffffffff816afcff>] path_mount+0xc8f/0x10d0 fs/namespace.c:3662
    [<ffffffff816b08f1>] do_mount fs/namespace.c:3675 [inline]
    [<ffffffff816b08f1>] __do_sys_mount fs/namespace.c:3884 [inline]
    [<ffffffff816b08f1>] __se_sys_mount fs/namespace.c:3861 [inline]
    [<ffffffff816b08f1>] __x64_sys_mount+0x1a1/0x1f0 fs/namespace.c:3861
    [<ffffffff84ad2bb8>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff84ad2bb8>] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80

BUG: memory leak
unreferenced object 0xffff8881260d4300 (size 96):
  comm "syz-executor.5", pid 7474, jiffies 4294960257 (age 171.960s)
  hex dump (first 32 bytes):
    00 10 10 00 00 00 00 00 00 10 00 00 00 00 00 00  ................
    01 00 00 00 00 00 00 00 01 00 00 00 01 00 00 00  ................
  backtrace:
    [<ffffffff815545e5>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1076
    [<ffffffff8217276e>] kmalloc include/linux/slab.h:582 [inline]
    [<ffffffff8217276e>] kzalloc include/linux/slab.h:703 [inline]
    [<ffffffff8217276e>] add_block_entry+0x4e/0x320 fs/btrfs/ref-verify.c:271
    [<ffffffff82172df6>] add_tree_block+0x96/0x240 fs/btrfs/ref-verify.c:332
    [<ffffffff821743f9>] process_extent_item fs/btrfs/ref-verify.c:474 [inline]
    [<ffffffff821743f9>] process_leaf fs/btrfs/ref-verify.c:521 [inline]
    [<ffffffff821743f9>] walk_down_tree fs/btrfs/ref-verify.c:573 [inline]
    [<ffffffff821743f9>] btrfs_build_ref_tree+0x589/0x850 fs/btrfs/ref-verify.c:1008
    [<ffffffff8205ec90>] open_ctree+0x1890/0x2270 fs/btrfs/disk-io.c:3471
    [<ffffffff8202582f>] btrfs_fill_super fs/btrfs/super.c:1154 [inline]
    [<ffffffff8202582f>] btrfs_mount_root+0x5af/0x750 fs/btrfs/super.c:1519
    [<ffffffff816d3e39>] legacy_get_tree+0x29/0x80 fs/fs_context.c:611
    [<ffffffff8166b7ea>] vfs_get_tree+0x2a/0x110 fs/super.c:1519
    [<ffffffff816a776b>] fc_mount fs/namespace.c:1112 [inline]
    [<ffffffff816a776b>] vfs_kern_mount.part.0+0xcb/0x110 fs/namespace.c:1142
    [<ffffffff816a77ef>] vfs_kern_mount+0x3f/0x60 fs/namespace.c:1129
    [<ffffffff820298b2>] btrfs_mount+0x1e2/0x660 fs/btrfs/super.c:1579
    [<ffffffff816d3e39>] legacy_get_tree+0x29/0x80 fs/fs_context.c:611
    [<ffffffff8166b7ea>] vfs_get_tree+0x2a/0x110 fs/super.c:1519
    [<ffffffff816afcff>] do_new_mount fs/namespace.c:3335 [inline]
    [<ffffffff816afcff>] path_mount+0xc8f/0x10d0 fs/namespace.c:3662
    [<ffffffff816b08f1>] do_mount fs/namespace.c:3675 [inline]
    [<ffffffff816b08f1>] __do_sys_mount fs/namespace.c:3884 [inline]
    [<ffffffff816b08f1>] __se_sys_mount fs/namespace.c:3861 [inline]
    [<ffffffff816b08f1>] __x64_sys_mount+0x1a1/0x1f0 fs/namespace.c:3861
    [<ffffffff84ad2bb8>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff84ad2bb8>] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80



Tested on:

commit:         25aa0beb Merge tag 'net-6.5-rc6' of git://git.kernel.o..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=11a0c5b7680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2bf8962e4f7984f4
dashboard link: https://syzkaller.appspot.com/bug?extid=d66de4cbf532749df35f
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1799b938e80000