[syzbot] [ocfs2?] kernel BUG in ocfs2_claim_suballoc_bits

[syzbot] [ocfs2?] kernel BUG in ocfs2_claim_suballoc_bits

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    872cf28b8df9 Merge tag 'platform-drivers-x86-v6.11-4' of g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15e78c33980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=df2f0ed7e30a639d
dashboard link: https://syzkaller.appspot.com/bug?extid=96d38c6e1655c1420a72
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1641940b980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17c6747b980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-872cf28b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e42852893b68/vmlinux-872cf28b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/99d0f54d6297/bzImage-872cf28b.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/7e59b3a54e83/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+96d38c6e1655c1420a72@syzkaller.appspotmail.com

         option from the mount to silence this warning.
=======================================================
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
------------[ cut here ]------------
kernel BUG at fs/ocfs2/suballoc.c:1441!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5092 Comm: syz-executor170 Not tainted 6.11.0-rc4-syzkaller-00033-g872cf28b8df9 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:ocfs2_find_victim_chain fs/ocfs2/suballoc.c:1441 [inline]
RIP: 0010:ocfs2_claim_suballoc_bits+0x240c/0x2570 fs/ocfs2/suballoc.c:1982
Code: 0a 12 05 fe 90 0f 0b e8 02 12 05 fe 90 0f 0b e8 fa 11 05 fe 90 0f 0b e8 f2 11 05 fe 90 0f 0b e8 4a 40 28 08 e8 e5 11 05 fe 90 <0f> 0b e8 dd 11 05 fe 90 0f 0b f3 0f 1e fa 65 8b 1d 9b 5d 75 7c bf
RSP: 0018:ffffc9000af36da0 EFLAGS: 00010293
RAX: ffffffff838e795b RBX: 0000000000000000 RCX: ffff88801c86c880
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000af37050 R08: ffffffff838e6445 R09: 0000000000000000
R10: ffffc9000af370e0 R11: fffff520015e6e21 R12: dffffc0000000000
R13: ffff88805f022008 R14: ffff88803f268400 R15: 0000000000000002
FS:  000055558fd61380(0000) GS:ffff888020800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001d86c000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ocfs2_claim_new_inode+0x338/0x870 fs/ocfs2/suballoc.c:2267
 ocfs2_mknod_locked+0x17a/0x3b0 fs/ocfs2/namei.c:633
 ocfs2_mknod+0x17d4/0x2b40 fs/ocfs2/namei.c:379
 ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
 lookup_open fs/namei.c:3578 [inline]
 open_last_lookups fs/namei.c:3647 [inline]
 path_openat+0x1a9a/0x3470 fs/namei.c:3883
 do_filp_open+0x235/0x490 fs/namei.c:3913
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1416
 do_sys_open fs/open.c:1431 [inline]
 __do_sys_openat fs/open.c:1447 [inline]
 __se_sys_openat fs/open.c:1442 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1442
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f40f4c89c59
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 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:00007ffc3348c8c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f40f4c89c59
RDX: 0000000000040942 RSI: 0000000020000200 RDI: 00000000ffffff9c
RBP: 00007f40f4d015f0 R08: 000055558fd624c0 R09: 000055558fd624c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc3348c8f0
R13: 00007ffc3348cb18 R14: 431bde82d7b634db R15: 00007f40f4cd203b
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ocfs2_find_victim_chain fs/ocfs2/suballoc.c:1441 [inline]
RIP: 0010:ocfs2_claim_suballoc_bits+0x240c/0x2570 fs/ocfs2/suballoc.c:1982
Code: 0a 12 05 fe 90 0f 0b e8 02 12 05 fe 90 0f 0b e8 fa 11 05 fe 90 0f 0b e8 f2 11 05 fe 90 0f 0b e8 4a 40 28 08 e8 e5 11 05 fe 90 <0f> 0b e8 dd 11 05 fe 90 0f 0b f3 0f 1e fa 65 8b 1d 9b 5d 75 7c bf
RSP: 0018:ffffc9000af36da0 EFLAGS: 00010293
RAX: ffffffff838e795b RBX: 0000000000000000 RCX: ffff88801c86c880
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000af37050 R08: ffffffff838e6445 R09: 0000000000000000
R10: ffffc9000af370e0 R11: fffff520015e6e21 R12: dffffc0000000000
R13: ffff88805f022008 R14: ffff88803f268400 R15: 0000000000000002
FS:  000055558fd61380(0000) GS:ffff888020800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001d86c000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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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.

If you want to overwrite report's subsystems, reply with:
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If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

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

Re: Syzbot test for fs: ocfs2: fix kernel BUG in ocfs2_find_victim_chain

[Prithvi Tambewagh]

#syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 939f15e640f193616691d3bcde0089760e75b0d3

Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
---
 fs/ocfs2/suballoc.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 6ac4dcd54588..c7eb6efc00b4 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -1993,6 +1993,13 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
 
 	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
 
+	if( le16_to_cpu(cl->cl_next_free_rec) == 0) {
+		status = ocfs2_error(ac->ac_inode->i_sb,
+				     "Chain allocator dinode %llu has 0 chains\n",
+				     (unsigned long long)le64_to_cpu(fe->i_blkno));
+		goto bail;
+	}
+
 	victim = ocfs2_find_victim_chain(cl);
 	ac->ac_chain = victim;
 

base-commit: 939f15e640f193616691d3bcde0089760e75b0d3
-- 
2.34.1

Re: Syzbot test for fs: ocfs2: fix kernel BUG in ocfs2_find_victim_chain

[syzbot]

> #syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 939f15e640f193616691d3bcde0089760e75b0d3

I see the command but can't find the corresponding bug.
Please resend the email to syzbot+HASH@syzkaller.appspotmail.com address
that is the sender of the bug report (also present in the Reported-by tag).

>
> Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
> ---
>  fs/ocfs2/suballoc.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
> index 6ac4dcd54588..c7eb6efc00b4 100644
> --- a/fs/ocfs2/suballoc.c
> +++ b/fs/ocfs2/suballoc.c
> @@ -1993,6 +1993,13 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
>  
>  	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
>  
> +	if( le16_to_cpu(cl->cl_next_free_rec) == 0) {
> +		status = ocfs2_error(ac->ac_inode->i_sb,
> +				     "Chain allocator dinode %llu has 0 chains\n",
> +				     (unsigned long long)le64_to_cpu(fe->i_blkno));
> +		goto bail;
> +	}
> +
>  	victim = ocfs2_find_victim_chain(cl);
>  	ac->ac_chain = victim;
>  
>
> base-commit: 939f15e640f193616691d3bcde0089760e75b0d3
> -- 
> 2.34.1
>
> -- 
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com.
> To view this discussion visit https://groups.google.com/d/msgid/syzkaller-bugs/20251129190507.543570-1-activprithvi%40gmail.com.

Re: Syzbot test for fs: ocfs2: fix kernel BUG in ocfs2_find_victim_chain

[Prithvi Tambewagh]

#syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 939f15e640f193616691d3bcde0089760e75b0d3

Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
---
 fs/ocfs2/suballoc.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 6ac4dcd54588..c7eb6efc00b4 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -1993,6 +1993,13 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
 
 	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
 
+	if( le16_to_cpu(cl->cl_next_free_rec) == 0) {
+		status = ocfs2_error(ac->ac_inode->i_sb,
+				     "Chain allocator dinode %llu has 0 chains\n",
+				     (unsigned long long)le64_to_cpu(fe->i_blkno));
+		goto bail;
+	}
+
 	victim = ocfs2_find_victim_chain(cl);
 	ac->ac_chain = victim;
 

base-commit: 939f15e640f193616691d3bcde0089760e75b0d3
-- 
2.34.1

Re: [syzbot] [ocfs2?] kernel BUG in ocfs2_claim_suballoc_bits

[syzbot]

Hello,

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

Reported-by: syzbot+96d38c6e1655c1420a72@syzkaller.appspotmail.com
Tested-by: syzbot+96d38c6e1655c1420a72@syzkaller.appspotmail.com

Tested on:

commit:         939f15e6 Merge tag 'turbostat-2025.06.08' of git://git..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=176614b4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=dcc9fa9d12bdc372
dashboard link: https://syzkaller.appspot.com/bug?extid=96d38c6e1655c1420a72
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=156ce112580000

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

Syzbot test for v2 for fs: ocfs2: fix kernel BUG in ocfs2_find_victim_chain

[Prithvi Tambewagh]

#syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 939f15e640f193616691d3bcde0089760e75b0d3

Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
---
 fs/ocfs2/suballoc.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 6ac4dcd54588..f4e4ef08e0f9 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -1992,6 +1992,13 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
 	}
 
 	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
+	if (!le16_to_cpu(cl->cl_next_free_rec) ||
+		le16_to_cpu(cl->cl_next_free_rec) > le16_to_cpu(cl->cl_count)) {
+		status = ocfs2_error(ac->ac_inode->i_sb,
+				     "Chain allocator dinode %llu has 0 chains\n",
+				     (unsigned long long)le64_to_cpu(fe->i_blkno));
+		goto bail;
+	}
 
 	victim = ocfs2_find_victim_chain(cl);
 	ac->ac_chain = victim;

base-commit: 939f15e640f193616691d3bcde0089760e75b0d3
-- 
2.34.1

Re: Syzbot test for v2 for fs: ocfs2: fix kernel BUG in ocfs2_find_victim_chain

[syzbot]

> #syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 939f15e640f193616691d3bcde0089760e75b0d3

I see the command but can't find the corresponding bug.
Please resend the email to syzbot+HASH@syzkaller.appspotmail.com address
that is the sender of the bug report (also present in the Reported-by tag).

>
> Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
> ---
>  fs/ocfs2/suballoc.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
> index 6ac4dcd54588..f4e4ef08e0f9 100644
> --- a/fs/ocfs2/suballoc.c
> +++ b/fs/ocfs2/suballoc.c
> @@ -1992,6 +1992,13 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
>  	}
>  
>  	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
> +	if (!le16_to_cpu(cl->cl_next_free_rec) ||
> +		le16_to_cpu(cl->cl_next_free_rec) > le16_to_cpu(cl->cl_count)) {
> +		status = ocfs2_error(ac->ac_inode->i_sb,
> +				     "Chain allocator dinode %llu has 0 chains\n",
> +				     (unsigned long long)le64_to_cpu(fe->i_blkno));
> +		goto bail;
> +	}
>  
>  	victim = ocfs2_find_victim_chain(cl);
>  	ac->ac_chain = victim;
>
> base-commit: 939f15e640f193616691d3bcde0089760e75b0d3
> -- 
> 2.34.1
>
> -- 
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com.
> To view this discussion visit https://groups.google.com/d/msgid/syzkaller-bugs/20251201073538.47128-1-activprithvi%40gmail.com.

Syzbot test for v2 for fs: ocfs2: fix kernel BUG in ocfs2_find_victim_chain

[Prithvi Tambewagh]

#syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 939f15e640f193616691d3bcde0089760e75b0d3

Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
---
 fs/ocfs2/suballoc.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 6ac4dcd54588..f4e4ef08e0f9 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -1992,6 +1992,13 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
 	}
 
 	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
+	if (!le16_to_cpu(cl->cl_next_free_rec) ||
+		le16_to_cpu(cl->cl_next_free_rec) > le16_to_cpu(cl->cl_count)) {
+		status = ocfs2_error(ac->ac_inode->i_sb,
+				     "Chain allocator dinode %llu has 0 chains\n",
+				     (unsigned long long)le64_to_cpu(fe->i_blkno));
+		goto bail;
+	}
 
 	victim = ocfs2_find_victim_chain(cl);
 	ac->ac_chain = victim;

base-commit: 939f15e640f193616691d3bcde0089760e75b0d3
-- 
2.34.1

Re: Syzbot test for v2 for fs: ocfs2: fix kernel BUG in ocfs2_find_victim_chain

[Joseph Qi]

On 2025/12/1 15:35, Prithvi Tambewagh wrote:
> #syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 939f15e640f193616691d3bcde0089760e75b0d3
> 
> Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
> ---
>  fs/ocfs2/suballoc.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
> index 6ac4dcd54588..f4e4ef08e0f9 100644
> --- a/fs/ocfs2/suballoc.c
> +++ b/fs/ocfs2/suballoc.c
> @@ -1992,6 +1992,13 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
>  	}
>  
>  	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
> +	if (!le16_to_cpu(cl->cl_next_free_rec) ||
> +		le16_to_cpu(cl->cl_next_free_rec) > le16_to_cpu(cl->cl_count)) {
	    ^
Prefer to align here.

BTW, the prefix for patch title can be "ocfs2: " only.

Joseph

> +		status = ocfs2_error(ac->ac_inode->i_sb,
> +				     "Chain allocator dinode %llu has 0 chains\n",
> +				     (unsigned long long)le64_to_cpu(fe->i_blkno));
> +		goto bail;
> +	}
>  
>  	victim = ocfs2_find_victim_chain(cl);
>  	ac->ac_chain = victim;
> 
> base-commit: 939f15e640f193616691d3bcde0089760e75b0d3

Re: [syzbot] [ocfs2?] kernel BUG in ocfs2_claim_suballoc_bits

[syzbot]

Hello,

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

Reported-by: syzbot+96d38c6e1655c1420a72@syzkaller.appspotmail.com
Tested-by: syzbot+96d38c6e1655c1420a72@syzkaller.appspotmail.com

Tested on:

commit:         939f15e6 Merge tag 'turbostat-2025.06.08' of git://git..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=15cfc512580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=dcc9fa9d12bdc372
dashboard link: https://syzkaller.appspot.com/bug?extid=96d38c6e1655c1420a72
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=14ac02b4580000

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

Syzbot test for v3: ocfs2: fix kernel BUG in ocfs2_find_victim_chain

[Prithvi Tambewagh]

#syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 939f15e640f193616691d3bcde0089760e75b0d3

Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
---
 fs/ocfs2/suballoc.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 6ac4dcd54588..c310345b7135 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -1992,6 +1992,14 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
 	}
 
 	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
+	if (!le16_to_cpu(cl->cl_next_free_rec) ||
+	    le16_to_cpu(cl->cl_next_free_rec) > le16_to_cpu(cl->cl_count)) {
+		status = ocfs2_error(ac->ac_inode->i_sb,
+				     "Chain allocator dinode %llu has invalid next "
+				     "free chain record %u, but only %u total\n",
+				     (unsigned long long)le64_to_cpu(fe->i_blkno),
+				     le16_to_cpu(cl->cl_next_free_rec),
+				     le16_to_cpu(cl->cl_count));
 
 	victim = ocfs2_find_victim_chain(cl);
 	ac->ac_chain = victim;

base-commit: 939f15e640f193616691d3bcde0089760e75b0d3
-- 
2.34.1

Re: [syzbot] [ocfs2?] kernel BUG in ocfs2_claim_suballoc_bits

[syzbot]

Hello,

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

fs/ocfs2/suballoc.c:2082:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2116:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2143:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2152:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2215:1: error: function definition is not allowed here
:2289:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2330:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2345:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2364:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2392:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2463:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2479:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2562:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2631:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2640:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2658:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2700:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2715:1: error: function definition is not allowed here
fs/ocfs2/suballoc.c:2736:1: error: function definition is not allowed here


Tested on:

commit:         939f15e6 Merge tag 'turbostat-2025.06.08' of git://git..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel config:  https://syzkaller.appspot.com/x/.config?x=d9ebb51ccc2ec42f
dashboard link: https://syzkaller.appspot.com/bug?extid=96d38c6e1655c1420a72
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=12782512580000

Syzbot test for v3: ocfs2: fix kernel BUG in ocfs2_find_victim_chain

[Prithvi Tambewagh]

#syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 939f15e640f193616691d3bcde0089760e75b0d3

Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
---
 fs/ocfs2/suballoc.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 6ac4dcd54588..6c2c33a26056 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -1992,6 +1992,15 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
 	}
 
 	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
+	if (!le16_to_cpu(cl->cl_next_free_rec) ||
+	    le16_to_cpu(cl->cl_next_free_rec) > le16_to_cpu(cl->cl_count)) {
+		status = ocfs2_error(ac->ac_inode->i_sb,
+				     "Chain allocator dinode %llu has invalid next "
+				     "free chain record %u, but only %u total\n",
+				     (unsigned long long)le64_to_cpu(fe->i_blkno),
+				     le16_to_cpu(cl->cl_next_free_rec),
+				     le16_to_cpu(cl->cl_count));
+	}
 
 	victim = ocfs2_find_victim_chain(cl);
 	ac->ac_chain = victim;

base-commit: 939f15e640f193616691d3bcde0089760e75b0d3
-- 
2.34.1

Re: [syzbot] [ocfs2?] kernel BUG in ocfs2_claim_suballoc_bits

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
kernel BUG in ocfs2_claim_suballoc_bits

ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
OCFS2: ERROR (device loop0): int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *, handle_t *, u32, u32, struct ocfs2_suballoc_result *): Chain allocator dinode 71 has invalid next free chain record 0, but only 0 total
On-disk corruption discovered. Please run fsck.ocfs2 once the filesystem is unmounted.
OCFS2: File system is now read-only.
------------[ cut here ]------------
kernel BUG at fs/ocfs2/suballoc.c:1443!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 6562 Comm: syz.0.16 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:ocfs2_find_victim_chain fs/ocfs2/suballoc.c:1443 [inline]
RIP: 0010:ocfs2_claim_suballoc_bits+0x25b9/0x25d0 fs/ocfs2/suballoc.c:2005
Code: 5f fb ff ff e8 08 41 1c fe 90 0f 0b e8 00 41 1c fe 90 0f 0b e8 f8 40 1c fe 90 0f 0b e8 f0 40 1c fe 90 0f 0b e8 e8 40 1c fe 90 <0f> 0b e8 e0 40 1c fe 90 0f 0b 66 66 66 66 2e 0f 1f 84 00 00 00 00
RSP: 0018:ffffc90003496e80 EFLAGS: 00010293
RAX: ffffffff83a40da8 RBX: 0000000000000000 RCX: ffff888025d78000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003497110 R08: ffff888072d4c103 R09: 1ffff1100e5a9820
R10: dffffc0000000000 R11: ffffed100e5a9821 R12: ffff88806f212ec4
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888072a78000
FS:  00007f6946c846c0(0000) GS:ffff888125c86000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2dd5ffff CR3: 0000000027c28000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __ocfs2_claim_clusters+0x303/0x8f0 fs/ocfs2/suballoc.c:2430
 ocfs2_local_alloc_new_window fs/ocfs2/localalloc.c:1166 [inline]
 ocfs2_local_alloc_slide_window fs/ocfs2/localalloc.c:1295 [inline]
 ocfs2_reserve_local_alloc_bits+0x12be/0x24e0 fs/ocfs2/localalloc.c:669
 ocfs2_reserve_clusters_with_limit+0x1be/0xba0 fs/ocfs2/suballoc.c:1168
 ocfs2_mknod+0xe32/0x2050 fs/ocfs2/namei.c:354
 ocfs2_mkdir+0x191/0x440 fs/ocfs2/namei.c:656
 vfs_mkdir+0x303/0x510 fs/namei.c:4366
 do_mkdirat+0x247/0x590 fs/namei.c:4399
 __do_sys_mkdirat fs/namei.c:4416 [inline]
 __se_sys_mkdirat fs/namei.c:4414 [inline]
 __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4414
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6945d8e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6946c84038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f6945fb5fa0 RCX: 00007f6945d8e929
RDX: 0000000000000081 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f6945e10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6945fb5fa0 R15: 00007ffc37f061f8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ocfs2_find_victim_chain fs/ocfs2/suballoc.c:1443 [inline]
RIP: 0010:ocfs2_claim_suballoc_bits+0x25b9/0x25d0 fs/ocfs2/suballoc.c:2005
Code: 5f fb ff ff e8 08 41 1c fe 90 0f 0b e8 00 41 1c fe 90 0f 0b e8 f8 40 1c fe 90 0f 0b e8 f0 40 1c fe 90 0f 0b e8 e8 40 1c fe 90 <0f> 0b e8 e0 40 1c fe 90 0f 0b 66 66 66 66 2e 0f 1f 84 00 00 00 00
RSP: 0018:ffffc90003496e80 EFLAGS: 00010293
RAX: ffffffff83a40da8 RBX: 0000000000000000 RCX: ffff888025d78000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003497110 R08: ffff888072d4c103 R09: 1ffff1100e5a9820
R10: dffffc0000000000 R11: ffffed100e5a9821 R12: ffff88806f212ec4
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888072a78000
FS:  00007f6946c846c0(0000) GS:ffff888125d86000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e32d8b1950 CR3: 0000000027c28000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


Tested on:

commit:         939f15e6 Merge tag 'turbostat-2025.06.08' of git://git..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=12f502b4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=dcc9fa9d12bdc372
dashboard link: https://syzkaller.appspot.com/bug?extid=96d38c6e1655c1420a72
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=12d958c2580000

Syzbot testing for v3: ocfs2: fix kernel BUG in ocfs2_find_victim_chain

[Prithvi Tambewagh]

#syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 939f15e640f193616691d3bcde0089760e75b0d3

Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
---
 fs/ocfs2/suballoc.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 6ac4dcd54588..e93fc842bb20 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -1992,6 +1992,16 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
 	}
 
 	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
+	if (!le16_to_cpu(cl->cl_next_free_rec) ||
+	    le16_to_cpu(cl->cl_next_free_rec) > le16_to_cpu(cl->cl_count)) {
+		status = ocfs2_error(ac->ac_inode->i_sb,
+				     "Chain allocator dinode %llu has invalid next "
+				     "free chain record %u, but only %u total\n",
+				     (unsigned long long)le64_to_cpu(fe->i_blkno),
+				     le16_to_cpu(cl->cl_next_free_rec),
+				     le16_to_cpu(cl->cl_count));
+		goto bail;
+	}
 
 	victim = ocfs2_find_victim_chain(cl);
 	ac->ac_chain = victim;

base-commit: 939f15e640f193616691d3bcde0089760e75b0d3
-- 
2.34.1

Re: [syzbot] [ocfs2?] kernel BUG in ocfs2_claim_suballoc_bits

[syzbot]

Hello,

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

Reported-by: syzbot+96d38c6e1655c1420a72@syzkaller.appspotmail.com
Tested-by: syzbot+96d38c6e1655c1420a72@syzkaller.appspotmail.com

Tested on:

commit:         939f15e6 Merge tag 'turbostat-2025.06.08' of git://git..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1657c192580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=dcc9fa9d12bdc372
dashboard link: https://syzkaller.appspot.com/bug?extid=96d38c6e1655c1420a72
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=11af4b6f980000

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