[v1] jfs: Add check for array bounds in dtDelete

[PATCH] jfs: Add check for array bounds in dtDelete

Posted by Pedro Demarchi Gomes 1 week, 6 days ago

#syz test

---
 fs/jfs/jfs_dtree.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/jfs/jfs_dtree.c b/fs/jfs/jfs_dtree.c
index ab11849cf9cc..b30f57304c09 100644
--- a/fs/jfs/jfs_dtree.c
+++ b/fs/jfs/jfs_dtree.c
@@ -2129,6 +2129,14 @@ int dtDelete(tid_t tid,
 					next_index = -1;
 				else {
 					stbl = DT_GETSTBL(np);
+					if (stbl[0] < 0 || stbl[0] >= DTPAGEMAXSLOT) {
+						jfs_err("JFS: Invalid stbl[0] = %d for inode %ld, block = %lld",
+							stbl[0], (long)ip->i_ino, (long long)le64_to_cpu(p->header.next));
+						DT_PUTPAGE(nmp);
+						DT_PUTPAGE(mp);
+						return -EIO;
+					}
+
 					ldtentry =
 					    (struct ldtentry *) & np->
 					    slot[stbl[0]];
-- 
2.39.5

Re: [syzbot] [jfs?] UBSAN: array-index-out-of-bounds in dtDelete

Posted by syzbot 1 week, 6 days ago

Hello,

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

------------[ cut here ]------------
kernel BUG at fs/jfs/inode.c:169!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5829 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:jfs_evict_inode+0x438/0x440 fs/jfs/inode.c:169
Code: fe e9 e0 fd ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 23 fe ff ff 4c 89 f7 e8 53 32 e8 fe e9 16 fe ff ff e8 a9 30 83 fe 90 <0f> 0b 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000294fae0 EFLAGS: 00010293
RAX: ffffffff833c7ea7 RBX: ffff888040f50430 RCX: ffff888000b00000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888040f50430
RBP: 0000000000000001 R08: ffffffff8fa1dc37 R09: 1ffffffff1f43b86
R10: dffffc0000000000 R11: ffffffff833c5ba0 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888040f500b8 R15: ffffffff833c7a70
FS:  0000555570297500(0000) GS:ffff88808d261000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd8d810d68 CR3: 00000000594b6000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 evict+0x504/0x9c0 fs/inode.c:810
 dispose_list fs/inode.c:852 [inline]
 evict_inodes+0x64c/0x6d0 fs/inode.c:906
 generic_shutdown_super+0x9a/0x2c0 fs/super.c:628
 kill_block_super+0x44/0x90 fs/super.c:1766
 deactivate_locked_super+0xb9/0x130 fs/super.c:474
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375
 task_work_run+0x1d1/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd644f8e497
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffd8d811518 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fd64500e08c RCX: 00007fd644f8e497
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd8d8115d0
RBP: 00007ffd8d8115d0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd8d812660
R13: 00007fd64500e08c R14: 0000000000023de4 R15: 00007ffd8d8126a0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:jfs_evict_inode+0x438/0x440 fs/jfs/inode.c:169
Code: fe e9 e0 fd ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 23 fe ff ff 4c 89 f7 e8 53 32 e8 fe e9 16 fe ff ff e8 a9 30 83 fe 90 <0f> 0b 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000294fae0 EFLAGS: 00010293
RAX: ffffffff833c7ea7 RBX: ffff888040f50430 RCX: ffff888000b00000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888040f50430
RBP: 0000000000000001 R08: ffffffff8fa1dc37 R09: 1ffffffff1f43b86
R10: dffffc0000000000 R11: ffffffff833c5ba0 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888040f500b8 R15: ffffffff833c7a70
FS:  0000555570297500(0000) GS:ffff88808d261000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c009bee020 CR3: 00000000594b6000 CR4: 0000000000352ef0


Tested on:

commit:         cbf658dd Merge tag 'net-6.17-rc7' of git://git.kernel...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1261cf62580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=839dff357af8f40d
dashboard link: https://syzkaller.appspot.com/bug?extid=4f9c823a6f63d87491ba
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=11123f62580000