[syzbot] [ext4?] kernel BUG in ext4_write_inline_data (2)

[syzbot] [ext4?] kernel BUG in ext4_write_inline_data (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    4a5df3796467 Merge tag 'mm-hotfixes-stable-2024-11-16-15-3..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=165adb5f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ca2f08f822652bd0
dashboard link: https://syzkaller.appspot.com/bug?extid=fe2a25dae02a207717a0
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=118eb2c0580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1395f130580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5912c1b48bcf/disk-4a5df379.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e9bdeba257b7/vmlinux-4a5df379.xz
kernel image: https://storage.googleapis.com/syzbot-assets/567e5bf968eb/bzImage-4a5df379.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/94e36b599391/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fe2a25dae02a207717a0@syzkaller.appspotmail.com

EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.
------------[ cut here ]------------
kernel BUG at fs/ext4/inline.c:235!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 1 UID: 0 PID: 5838 Comm: syz-executor116 Not tainted 6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
RIP: 0010:ext4_write_inline_data+0x36b/0x460 fs/ext4/inline.c:235
Code: df 41 ff e8 f7 df 41 ff 45 8d 64 2c c4 b8 3c 00 00 00 29 e8 4c 63 f0 e9 c7 fe ff ff e8 de df 41 ff 90 0f 0b e8 d6 df 41 ff 90 <0f> 0b e8 8e b8 a2 ff e9 d6 fd ff ff 4c 89 ff e8 81 b8 a2 ff e9 71
RSP: 0018:ffffc90003e078e0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888074c38c98 RCX: ffffffff824b9874
RDX: ffff8880349bbc00 RSI: ffffffff824b9a7a RDI: 0000000000000006
RBP: 0000010000000005 R08: 0000000000000006 R09: 0000010000000006
R10: 000000000000003c R11: 0000000000000000 R12: 0000000000000001
R13: ffffc90003e07980 R14: 0000010000000006 R15: ffff888074c39242
FS:  00005555714a8380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000066c7e0 CR3: 0000000077348000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 ext4_write_inline_data_end+0x278/0xc50 fs/ext4/inline.c:774
 ext4_da_write_end+0x54e/0xd00 fs/ext4/inode.c:3065
 generic_perform_write+0x4e8/0x920 mm/filemap.c:4069
 ext4_buffered_write_iter+0x119/0x3c0 fs/ext4/file.c:299
 ext4_file_write_iter+0x861/0x19d0 fs/ext4/file.c:698
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0x5b1/0x1150 fs/read_write.c:683
 ksys_pwrite64 fs/read_write.c:798 [inline]
 __do_sys_pwrite64 fs/read_write.c:808 [inline]
 __se_sys_pwrite64 fs/read_write.c:805 [inline]
 __x64_sys_pwrite64+0x200/0x260 fs/read_write.c:805
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f18e1c07679
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff5a649ea8 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007fff5a64a078 RCX: 00007f18e1c07679
RDX: 0000000000000001 RSI: 0000000020000300 RDI: 0000000000000004
RBP: 00007f18e1c7b610 R08: 0000000000000000 R09: 00007fff5a64a078
R10: 0000010000000005 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff5a64a068 R14: 0000000000000001 R15: 0000000000000001
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_write_inline_data+0x36b/0x460 fs/ext4/inline.c:235
Code: df 41 ff e8 f7 df 41 ff 45 8d 64 2c c4 b8 3c 00 00 00 29 e8 4c 63 f0 e9 c7 fe ff ff e8 de df 41 ff 90 0f 0b e8 d6 df 41 ff 90 <0f> 0b e8 8e b8 a2 ff e9 d6 fd ff ff 4c 89 ff e8 81 b8 a2 ff e9 71
RSP: 0018:ffffc90003e078e0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888074c38c98 RCX: ffffffff824b9874
RDX: ffff8880349bbc00 RSI: ffffffff824b9a7a RDI: 0000000000000006
RBP: 0000010000000005 R08: 0000000000000006 R09: 0000010000000006
R10: 000000000000003c R11: 0000000000000000 R12: 0000000000000001
R13: ffffc90003e07980 R14: 0000010000000006 R15: ffff888074c39242
FS:  00005555714a8380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5524d17095 CR3: 0000000077348000 CR4: 0000000000350ef0


---
This report is generated by a bot. It may contain errors.
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If the report is already addressed, 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.

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If the report is a duplicate of another one, reply with:
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If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] [ext4?] kernel BUG in ext4_write_inline_data (2)

[syzbot]

Hello,

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

Reported-by: syzbot+fe2a25dae02a207717a0@syzkaller.appspotmail.com
Tested-by: syzbot+fe2a25dae02a207717a0@syzkaller.appspotmail.com

Tested on:

commit:         43fb83c1 Merge tag 'soc-arm-6.13' of git://git.kernel...
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=12c05930580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1638cad79464dac0
dashboard link: https://syzkaller.appspot.com/bug?extid=fe2a25dae02a207717a0
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=149beb78580000

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

Re: [syzbot] [ext4?] kernel BUG in ext4_write_inline_data (2)

[syzbot]

Hello,

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

failed to apply patch:
checking file fs/ext4/ext4.h
patch: **** malformed patch at line 8: diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c




Tested on:

commit:         28eb75e1 Merge tag 'drm-next-2024-11-21' of https://gi..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=ca2f08f822652bd0
dashboard link: https://syzkaller.appspot.com/bug?extid=fe2a25dae02a207717a0
compiler:       
patch:          https://syzkaller.appspot.com/x/patch.diff?x=10ea7ec0580000

Re: [syzbot] [ext4?] kernel BUG in ext4_write_inline_data (2)

[syzbot]

Hello,

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

failed to apply patch:
checking file fs/ext4/ext4.h
patch: **** malformed patch at line 6: diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c




Tested on:

commit:         28eb75e1 Merge tag 'drm-next-2024-11-21' of https://gi..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=ca2f08f822652bd0
dashboard link: https://syzkaller.appspot.com/bug?extid=fe2a25dae02a207717a0
compiler:       
patch:          https://syzkaller.appspot.com/x/patch.diff?x=14b6db78580000

Re: [syzbot] [ext4?] kernel BUG in ext4_write_inline_data (2)

[Nicolas Bretz]

#syz test

--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3562,6 +3562,12 @@ extern int ext4_get_max_inline_size(struct inode *inode);
 extern int ext4_find_inline_data_nolock(struct inode *inode);
 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);

+static inline bool ext4_inline_possible(struct inode *inode,
+ loff_t pos, unsigned int len)
+{
+ return pos + len <= ext4_get_max_inline_size(inode);
+}
+
 int ext4_readpage_inline(struct inode *inode, struct folio *folio);
 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
  struct inode *inode,
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -668,7 +668,7 @@ int ext4_try_to_write_inline_data(struct
address_space *mapping,
  struct folio *folio;
  struct ext4_iloc iloc;

- if (pos + len > ext4_get_max_inline_size(inode))
+ if (!ext4_inline_possible(inode, pos, len))
  goto convert;

  ret = ext4_get_inode_loc(inode, &iloc);
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3061,7 +3061,8 @@ static int ext4_da_write_end(struct file *file,

  if (write_mode != CONVERT_INLINE_DATA &&
      ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) &&
-     ext4_has_inline_data(inode))
+     ext4_has_inline_data(inode) &&
+     ext4_inline_possible(inode, pos, len))
  return ext4_write_inline_data_end(inode, pos, len, copied,
    folio);

Re: [syzbot] [ext4?] kernel BUG in ext4_write_inline_data (2)

[syzbot]

Hello,

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

failed to apply patch:
checking file fs/ext4/ext4.h
patch: **** malformed patch at line 8: @@ -668,7 +668,7 @@ int ext4_try_to_write_inline_data(struct




Tested on:

commit:         28eb75e1 Merge tag 'drm-next-2024-11-21' of https://gi..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=ca2f08f822652bd0
dashboard link: https://syzkaller.appspot.com/bug?extid=fe2a25dae02a207717a0
compiler:       
patch:          https://syzkaller.appspot.com/x/patch.diff?x=140ddb78580000

Re: [syzbot] [ext4?] kernel BUG in ext4_write_inline_data (2)

[Nicolas Bretz]

[-- Attachment #1: Type: text/plain, Size: 10 bytes --]

#syz test

[-- Attachment #2: 0002-ext4-kernel-BUG-in-ext4_write_inline_data.patch --]
[-- Type: text/x-patch, Size: 2187 bytes --]

From f4baf29ec7942e89f010133d7e848ba69d7f77f1 Mon Sep 17 00:00:00 2001
From: Nicolas Bretz <bretznic@gmail.com>
Date: Fri, 22 Nov 2024 08:23:38 -0700
Subject: [PATCH] ext4: kernel BUG in ext4_write_inline_data

kernel BUG at fs/ext4/inline.c:235!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI

Reported-by: syzbot+fe2a25dae02a207717a0@syzkaller.appspotmail.com
Signed-off-by: Nicolas Bretz <bretznic@gmail.com>
---
 fs/ext4/ext4.h   | 6 ++++++
 fs/ext4/inline.c | 2 +-
 fs/ext4/inode.c  | 3 ++-
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 44b0d418143c..b9d128243286 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3562,6 +3562,12 @@ extern int ext4_get_max_inline_size(struct inode *inode);
 extern int ext4_find_inline_data_nolock(struct inode *inode);
 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
 
+static inline bool ext4_inline_possible(struct inode *inode,
+					loff_t pos, unsigned int len)
+{
+	return pos + len <= ext4_get_max_inline_size(inode);
+}
+
 int ext4_readpage_inline(struct inode *inode, struct folio *folio);
 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
 					 struct inode *inode,
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 3536ca7e4fcc..ec25f066a2c2 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -668,7 +668,7 @@ int ext4_try_to_write_inline_data(struct address_space *mapping,
 	struct folio *folio;
 	struct ext4_iloc iloc;
 
-	if (pos + len > ext4_get_max_inline_size(inode))
+	if (!ext4_inline_possible(inode, pos, len))
 		goto convert;
 
 	ret = ext4_get_inode_loc(inode, &iloc);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 54bdd4884fe6..d4c0e0a42b8e 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3061,7 +3061,8 @@ static int ext4_da_write_end(struct file *file,
 
 	if (write_mode != CONVERT_INLINE_DATA &&
 	    ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) &&
-	    ext4_has_inline_data(inode))
+	    ext4_has_inline_data(inode) &&
+	    ext4_inline_possible(inode, pos, len))
 		return ext4_write_inline_data_end(inode, pos, len, copied,
 						  folio);
 
-- 
2.39.5

Re: [syzbot] [ext4?] kernel BUG in ext4_write_inline_data (2)

[syzbot]

Hello,

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

Reported-by: syzbot+fe2a25dae02a207717a0@syzkaller.appspotmail.com
Tested-by: syzbot+fe2a25dae02a207717a0@syzkaller.appspotmail.com

Tested on:

commit:         28eb75e1 Merge tag 'drm-next-2024-11-21' of https://gi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=127f7ec0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=461a3713d88227a7
dashboard link: https://syzkaller.appspot.com/bug?extid=fe2a25dae02a207717a0
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=12a586e8580000

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