On Thu, 04 May 2023 12:15:25 +0000, Tudor Ambarus wrote: > When modifying the block device while it is mounted by the filesystem, > syzbot reported the following: > > BUG: KASAN: slab-out-of-bounds in crc16+0x206/0x280 lib/crc16.c:58 > Read of size 1 at addr ffff888075f5c0a8 by task syz-executor.2/15586 > > CPU: 1 PID: 15586 Comm: syz-executor.2 Not tainted 6.2.0-rc5-syzkaller-00205-gc96618275234 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:88 [inline] > dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106 > print_address_description+0x74/0x340 mm/kasan/report.c:306 > print_report+0x107/0x1f0 mm/kasan/report.c:417 > kasan_report+0xcd/0x100 mm/kasan/report.c:517 > crc16+0x206/0x280 lib/crc16.c:58 > ext4_group_desc_csum+0x81b/0xb20 fs/ext4/super.c:3187 > ext4_group_desc_csum_set+0x195/0x230 fs/ext4/super.c:3210 > ext4_mb_clear_bb fs/ext4/mballoc.c:6027 [inline] > ext4_free_blocks+0x191a/0x2810 fs/ext4/mballoc.c:6173 > ext4_remove_blocks fs/ext4/extents.c:2527 [inline] > ext4_ext_rm_leaf fs/ext4/extents.c:2710 [inline] > ext4_ext_remove_space+0x24ef/0x46a0 fs/ext4/extents.c:2958 > ext4_ext_truncate+0x177/0x220 fs/ext4/extents.c:4416 > ext4_truncate+0xa6a/0xea0 fs/ext4/inode.c:4342 > ext4_setattr+0x10c8/0x1930 fs/ext4/inode.c:5622 > notify_change+0xe50/0x1100 fs/attr.c:482 > do_truncate+0x200/0x2f0 fs/open.c:65 > handle_truncate fs/namei.c:3216 [inline] > do_open fs/namei.c:3561 [inline] > path_openat+0x272b/0x2dd0 fs/namei.c:3714 > do_filp_open+0x264/0x4f0 fs/namei.c:3741 > do_sys_openat2+0x124/0x4e0 fs/open.c:1310 > do_sys_open fs/open.c:1326 [inline] > __do_sys_creat fs/open.c:1402 [inline] > __se_sys_creat fs/open.c:1396 [inline] > __x64_sys_creat+0x11f/0x160 fs/open.c:1396 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > RIP: 0033:0x7f72f8a8c0c9 > Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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:00007f72f97e3168 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 > RAX: ffffffffffffffda RBX: 00007f72f8bac050 RCX: 00007f72f8a8c0c9 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000280 > RBP: 00007f72f8ae7ae9 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > R13: 00007ffd165348bf R14: 00007f72f97e3300 R15: 0000000000022000 > > [...] Applied, thanks! [1/1] ext4: Avoid a potential slab-out-of-bounds in ext4_group_desc_csum commit: 707548336a9a5b1745074265c4d4d2cf2b4b0f43 Best regards, -- Theodore Ts'o <tytso@xxxxxxx>