[syzbot] [btrfs?] memory leak in btrfs_add_delayed_tree_ref

syzbot
2023-11-06T17:58:35Z

Hello,

syzbot found the following issue on:

HEAD commit: 8f6f76a6a29f Merge tag 'mm-nonmm-stable-2023-11-02-14-08' ..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15169b87680000
kernel config: https://syzkaller.appspot.com/x/.config?x=5ea2285f517f94d0
dashboard link: https://syzkaller.appspot.com/bug?extid=d3ddc6dcc6386dea398b
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=179c2ecf680000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=149dff40e80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/dfead0cc157b/disk-8f6f76a6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c2ab876430bc/vmlinux-8f6f76a6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e9cd314888e8/bzImage-8f6f76a6.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/4a497ff0ef1a/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d3ddc6dcc6386dea398b@syzkaller.appspotmail.com

executing program
BUG: memory leak
unreferenced object 0xffff88810891e940 (size 64):
comm "syz-executor244", pid 5031, jiffies 4294941874 (age 13.150s)
hex dump (first 32 bytes):
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 e0 51 00 00 00 00 00 ..........Q.....
backtrace:
[<ffffffff816336ad>] kmemleak_alloc_recursive include/linux/kmemleak.h:42 [inline]
[<ffffffff816336ad>] slab_post_alloc_hook mm/slab.h:766 [inline]
[<ffffffff816336ad>] slab_alloc_node mm/slub.c:3478 [inline]
[<ffffffff816336ad>] __kmem_cache_alloc_node+0x2dd/0x3f0 mm/slub.c:3517
[<ffffffff8157e505>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1098
[<ffffffff82135480>] kmalloc include/linux/slab.h:600 [inline]
[<ffffffff82135480>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff82135480>] btrfs_add_delayed_tree_ref+0x550/0x5b0 fs/btrfs/delayed-ref.c:1045
[<ffffffff820874bb>] btrfs_alloc_tree_block+0x65b/0x7c0 fs/btrfs/extent-tree.c:5153
[<ffffffff8206c15e>] btrfs_force_cow_block+0x1be/0xb30 fs/btrfs/ctree.c:563
[<ffffffff8206cbf8>] btrfs_cow_block+0x128/0x3b0 fs/btrfs/ctree.c:741
[<ffffffff82073609>] btrfs_search_slot+0xa49/0x1770 fs/btrfs/ctree.c:2095
[<ffffffff82074fa3>] btrfs_insert_empty_items+0x43/0xc0 fs/btrfs/ctree.c:4285
[<ffffffff820b8a34>] btrfs_create_new_inode+0x354/0xfe0 fs/btrfs/inode.c:6283
[<ffffffff820b99e7>] btrfs_create_common+0xf7/0x190 fs/btrfs/inode.c:6511
[<ffffffff820b9c12>] btrfs_create+0x72/0x90 fs/btrfs/inode.c:6551
[<ffffffff816b673f>] lookup_open fs/namei.c:3477 [inline]
[<ffffffff816b673f>] open_last_lookups fs/namei.c:3546 [inline]
[<ffffffff816b673f>] path_openat+0x17df/0x1d60 fs/namei.c:3776
[<ffffffff816b78e1>] do_filp_open+0xd1/0x1c0 fs/namei.c:3809
[<ffffffff816906c4>] do_sys_openat2+0xf4/0x150 fs/open.c:1440
[<ffffffff81690ec5>] do_sys_open fs/open.c:1455 [inline]
[<ffffffff81690ec5>] __do_sys_open fs/open.c:1463 [inline]
[<ffffffff81690ec5>] __se_sys_open fs/open.c:1459 [inline]
[<ffffffff81690ec5>] __x64_sys_open+0xa5/0xf0 fs/open.c:1459
[<ffffffff84b5dd4f>] do_syscall_x64 arch/x86/entry/common.c:51 [inline]
[<ffffffff84b5dd4f>] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82

BUG: memory leak
unreferenced object 0xffff88810891e980 (size 64):
comm "syz-executor244", pid 5031, jiffies 4294941874 (age 13.150s)
hex dump (first 32 bytes):
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 69 00 00 00 00 00 ..........i.....
backtrace:
[<ffffffff816336ad>] kmemleak_alloc_recursive include/linux/kmemleak.h:42 [inline]
[<ffffffff816336ad>] slab_post_alloc_hook mm/slab.h:766 [inline]
[<ffffffff816336ad>] slab_alloc_node mm/slub.c:3478 [inline]
[<ffffffff816336ad>] __kmem_cache_alloc_node+0x2dd/0x3f0 mm/slub.c:3517
[<ffffffff8157e505>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1098
[<ffffffff82135480>] kmalloc include/linux/slab.h:600 [inline]
[<ffffffff82135480>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff82135480>] btrfs_add_delayed_tree_ref+0x550/0x5b0 fs/btrfs/delayed-ref.c:1045
[<ffffffff82083f81>] btrfs_free_tree_block+0x131/0x450 fs/btrfs/extent-tree.c:3432
[<ffffffff8206c678>] btrfs_force_cow_block+0x6d8/0xb30 fs/btrfs/ctree.c:618
[<ffffffff8206cbf8>] btrfs_cow_block+0x128/0x3b0 fs/btrfs/ctree.c:741
[<ffffffff82073609>] btrfs_search_slot+0xa49/0x1770 fs/btrfs/ctree.c:2095
[<ffffffff82074fa3>] btrfs_insert_empty_items+0x43/0xc0 fs/btrfs/ctree.c:4285
[<ffffffff820b8a34>] btrfs_create_new_inode+0x354/0xfe0 fs/btrfs/inode.c:6283
[<ffffffff820b99e7>] btrfs_create_common+0xf7/0x190 fs/btrfs/inode.c:6511
[<ffffffff820b9c12>] btrfs_create+0x72/0x90 fs/btrfs/inode.c:6551
[<ffffffff816b673f>] lookup_open fs/namei.c:3477 [inline]
[<ffffffff816b673f>] open_last_lookups fs/namei.c:3546 [inline]
[<ffffffff816b673f>] path_openat+0x17df/0x1d60 fs/namei.c:3776
[<ffffffff816b78e1>] do_filp_open+0xd1/0x1c0 fs/namei.c:3809
[<ffffffff816906c4>] do_sys_openat2+0xf4/0x150 fs/open.c:1440
[<ffffffff81690ec5>] do_sys_open fs/open.c:1455 [inline]
[<ffffffff81690ec5>] __do_sys_open fs/open.c:1463 [inline]
[<ffffffff81690ec5>] __se_sys_open fs/open.c:1459 [inline]
[<ffffffff81690ec5>] __x64_sys_open+0xa5/0xf0 fs/open.c:1459
[<ffffffff84b5dd4f>] do_syscall_x64 arch/x86/entry/common.c:51 [inline]
[<ffffffff84b5dd4f>] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82

BUG: memory leak
unreferenced object 0xffff88810891ea00 (size 64):
comm "syz-executor244", pid 5031, jiffies 4294941874 (age 13.150s)
hex dump (first 32 bytes):
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 f0 51 00 00 00 00 00 ..........Q.....
backtrace:
[<ffffffff816336ad>] kmemleak_alloc_recursive include/linux/kmemleak.h:42 [inline]
[<ffffffff816336ad>] slab_post_alloc_hook mm/slab.h:766 [inline]
[<ffffffff816336ad>] slab_alloc_node mm/slub.c:3478 [inline]
[<ffffffff816336ad>] __kmem_cache_alloc_node+0x2dd/0x3f0 mm/slub.c:3517
[<ffffffff8157e505>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1098
[<ffffffff82135480>] kmalloc include/linux/slab.h:600 [inline]
[<ffffffff82135480>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff82135480>] btrfs_add_delayed_tree_ref+0x550/0x5b0 fs/btrfs/delayed-ref.c:1045
[<ffffffff820874bb>] btrfs_alloc_tree_block+0x65b/0x7c0 fs/btrfs/extent-tree.c:5153
[<ffffffff8206c15e>] btrfs_force_cow_block+0x1be/0xb30 fs/btrfs/ctree.c:563
[<ffffffff8206cbf8>] btrfs_cow_block+0x128/0x3b0 fs/btrfs/ctree.c:741
[<ffffffff82073609>] btrfs_search_slot+0xa49/0x1770 fs/btrfs/ctree.c:2095
[<ffffffff82074fa3>] btrfs_insert_empty_items+0x43/0xc0 fs/btrfs/ctree.c:4285
[<ffffffff820b8a34>] btrfs_create_new_inode+0x354/0xfe0 fs/btrfs/inode.c:6283
[<ffffffff820b99e7>] btrfs_create_common+0xf7/0x190 fs/btrfs/inode.c:6511
[<ffffffff820b9c12>] btrfs_create+0x72/0x90 fs/btrfs/inode.c:6551
[<ffffffff816b673f>] lookup_open fs/namei.c:3477 [inline]
[<ffffffff816b673f>] open_last_lookups fs/namei.c:3546 [inline]
[<ffffffff816b673f>] path_openat+0x17df/0x1d60 fs/namei.c:3776
[<ffffffff816b78e1>] do_filp_open+0xd1/0x1c0 fs/namei.c:3809
[<ffffffff816906c4>] do_sys_openat2+0xf4/0x150 fs/open.c:1440
[<ffffffff81690ec5>] do_sys_open fs/open.c:1455 [inline]
[<ffffffff81690ec5>] __do_sys_open fs/open.c:1463 [inline]
[<ffffffff81690ec5>] __se_sys_open fs/open.c:1459 [inline]
[<ffffffff81690ec5>] __x64_sys_open+0xa5/0xf0 fs/open.c:1459
[<ffffffff84b5dd4f>] do_syscall_x64 arch/x86/entry/common.c:51 [inline]
[<ffffffff84b5dd4f>] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82

---
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