| Message ID | 20240927165132.17289-1-rbrasga@uci.edu |
|---|---|
| State | Rejected |
| Headers | show |
| Series | ext4: WARNING: locking bug in ext4_ioctl | expand |
Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: WARNING: locking bug in ext4_ioctl loop0: detected capacity change from 0 to 512 ext4 filesystem being mounted at /root/syzkaller-testdir500386566/syzkaller.6PgxEV/36/bus supports timestamps until 2038-01-19 (0x7fffffff) ------------[ cut here ]------------ Looking for class "&ei->i_data_sem" with key init_once.__key.799, but found a different class "&ei->i_data_sem" with the same key WARNING: CPU: 1 PID: 5815 at kernel/locking/lockdep.c:939 look_up_lock_class+0xdc/0x170 kernel/locking/lockdep.c:936 Modules linked in: CPU: 1 UID: 0 PID: 5815 Comm: syz-executor.0 Not tainted 6.11.0-syzkaller-11673-geee280841e1c-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:look_up_lock_class+0xdc/0x170 kernel/locking/lockdep.c:936 Code: 01 0f 85 8a 00 00 00 c6 05 b3 f8 46 04 01 90 49 8b 16 49 8b 76 18 48 8b 8b b8 00 00 00 48 c7 c7 60 ea ea 8b e8 75 2c bf f5 90 <0f> 0b 90 90 eb 61 90 e8 08 44 18 f9 e8 53 5e de f5 48 c7 c7 a0 e9 RSP: 0018:ffffc900049ef4f0 EFLAGS: 00010046 RAX: 3592bb3d4927ad00 RBX: ffffffff931c0730 RCX: ffff888027c18000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900049ef600 R08: ffffffff8155a9c2 R09: 1ffff1101722519a R10: dffffc0000000000 R11: ffffed101722519b R12: ffff888077aadbb0 R13: ffff888077aadbb0 R14: ffff888077aadbb0 R15: ffffffff94d9f1c1 FS: 00007f214c1256c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002000e000 CR3: 0000000027aec000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> register_lock_class+0x102/0x980 kernel/locking/lockdep.c:1290 __lock_acquire+0xf0/0x2050 kernel/locking/lockdep.c:5074 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822 down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1695 swap_inode_boot_loader fs/ext4/ioctl.c:432 [inline] __ext4_ioctl fs/ext4/ioctl.c:1436 [inline] ext4_ioctl+0x4124/0x5590 fs/ext4/ioctl.c:1626 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 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: 0033:0x7f214b47dea9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f214c1250c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f214b5abf80 RCX: 00007f214b47dea9 RDX: 0000000000000000 RSI: 0000000000006611 RDI: 0000000000000004 RBP: 00007f214b4ca4a4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f214b5abf80 R15: 00007fff61b66448 </TASK> Tested on: commit: eee28084 Merge tag 'mm-hotfixes-stable-2024-09-27-09-4.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=161cde27980000 kernel config: https://syzkaller.appspot.com/x/.config?x=6e73c530afb43e82 dashboard link: https://syzkaller.appspot.com/bug?extid=a3c8e9ac9f9d77240afd compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 patch: https://syzkaller.appspot.com/x/patch.diff?x=17082507980000
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index e0e1956dcdd3..2b30b9571fd8 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -124,8 +124,12 @@ void ext4_xattr_inode_set_class(struct inode *ea_inode) struct ext4_inode_info *ei = EXT4_I(ea_inode); lockdep_set_subclass(&ea_inode->i_rwsem, 1); - (void) ei; /* shut up clang warning if !CONFIG_LOCKDEP */ - lockdep_set_subclass(&ei->i_data_sem, I_DATA_SEM_EA); + + if (ei->i_flags & EXT4_EA_INODE_FL) { + lockdep_set_subclass(&ei->i_data_sem, I_DATA_SEM_EA); + } else { + lockdep_set_subclass(&ei->i_data_sem, I_DATA_SEM_NORMAL); + } } #endif
Fixed the locking bug with the bisection found by syzbot. Link to the syzbot bug report: https://syzkaller.appspot.com/bug?extid=a3c8e9ac9f9d77240afd Reported-by: syzbot+a3c8e9ac9f9d77240afd@syzkaller.appspotmail.com Signed-off-by: Remington Brasga <rbrasga@uci.edu> --- First attempt at patching this issue. Verified the bug exists, and that this patch fixes it, and EXT4 KUnit tests pass. Though I am not sure if the patch should be higher up the stack. Open to questions or any suggestions for improvements. #syz test fs/ext4/xattr.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)