Dear Linux Developers, Recently, when using our tool to fuzz kernel, the following crash was triggered. HEAD commit: e45fb347b630 Linux 6.1.0-next-20221220 git tree: linux-next compiler: clang 12.0.0 console output: https://drive.google.com/file/d/1gh6F0I93Cdy8zQ1tv-L5kCaBGkd2tXhp/view?usp=share_link kernel config: https://drive.google.com/file/d/1mMD6aopttKDGK4aYUlgiwAk6bOQHivd-/view?usp=share_link Unfortunately, I didn't find a reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: Wei Chen <harperchen1110@xxxxxxxxx> list_add corruption. prev is NULL. ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:24! invalid opcode: 0000 [#1] PREEMPT SMP CPU: 0 PID: 19499 Comm: syz-executor.0 Not tainted 6.1.0-next-20221220 #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-48-gd9c812dda519-prebuilt.qemu.org 04/01/2014 RIP: 0010:__list_add_valid+0x73/0xc0 lib/list_debug.c:23 Code: 41 5f c3 48 c7 c7 70 3d 65 85 4c 89 fe 48 89 da 4c 89 f1 31 c0 e8 0d 2f 02 03 0f 0b 48 c7 c7 6f 3c 65 85 31 c0 e8 fd 2e 02 03 <0f> 0b 48 c7 c7 a6 3c 65 85 31 c0 e8 ed 2e 02 03 0f 0b 48 c7 c7 cc RSP: 0018:ffffc90005b97730 EFLAGS: 00010246 RAX: 0000000000000022 RBX: ffff88800a6257e8 RCX: 113c3aae3e481700 RDX: ffffc90000b35000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: 0000000000000000 R08: ffffffff81179fd9 R09: 0000000000000000 R10: 0001ffffffffffff R11: 000188807dc1b588 R12: ffff88800945a6d8 R13: ffff88800a6257e0 R14: ffff88800945a678 R15: 00000000000001e0 FS: 00007fc40c27d700(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31522000 CR3: 000000005ccbd000 CR4: 00000000003506f0 DR0: 0000000020000140 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: <TASK> __list_add include/linux/list.h:69 [inline] list_add_tail include/linux/list.h:102 [inline] mb_update_avg_fragment_size+0x26c/0x2e0 fs/ext4/mballoc.c:849 mb_mark_used+0xb5c/0xcc0 fs/ext4/mballoc.c:1958 ext4_mb_use_best_found+0x105/0x440 fs/ext4/mballoc.c:1979 ext4_mb_find_by_goal+0x58b/0x660 ext4_mb_regular_allocator+0x126/0x1e00 fs/ext4/mballoc.c:2614 ext4_mb_new_blocks+0x828/0x1240 fs/ext4/mballoc.c:5605 ext4_ext_map_blocks+0x1545/0x1f20 fs/ext4/extents.c:4286 ext4_map_blocks+0x748/0x1060 fs/ext4/inode.c:651 ext4_alloc_file_blocks+0x285/0x720 fs/ext4/extents.c:4470 ext4_fallocate+0x2c5/0x570 fs/ext4/extents.c:4757 vfs_fallocate+0x486/0x710 fs/open.c:323 ksys_fallocate fs/open.c:346 [inline] __do_sys_fallocate fs/open.c:354 [inline] __se_sys_fallocate fs/open.c:352 [inline] __x64_sys_fallocate+0x75/0xc0 fs/open.c:352 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x4697f9 Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc40c27cc48 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 000000000077bf80 RCX: 00000000004697f9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000006 RBP: 00000000004d29e9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000080000941 R11: 0000000000000246 R12: 000000000077bf80 R13: 0000000000000000 R14: 000000000077bf80 R15: 00007ffd6cd30fb0 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__list_add_valid+0x73/0xc0 lib/list_debug.c:23 Code: 41 5f c3 48 c7 c7 70 3d 65 85 4c 89 fe 48 89 da 4c 89 f1 31 c0 e8 0d 2f 02 03 0f 0b 48 c7 c7 6f 3c 65 85 31 c0 e8 fd 2e 02 03 <0f> 0b 48 c7 c7 a6 3c 65 85 31 c0 e8 ed 2e 02 03 0f 0b 48 c7 c7 cc RSP: 0018:ffffc90005b97730 EFLAGS: 00010246 RAX: 0000000000000022 RBX: ffff88800a6257e8 RCX: 113c3aae3e481700 RDX: ffffc90000b35000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: 0000000000000000 R08: ffffffff81179fd9 R09: 0000000000000000 R10: 0001ffffffffffff R11: 000188807dc1b588 R12: ffff88800945a6d8 R13: ffff88800a6257e0 R14: ffff88800945a678 R15: 00000000000001e0 FS: 00007fc40c27d700(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31522000 CR3: 000000005ccbd000 CR4: 00000000003506f0 DR0: 0000000020000140 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Best, Wei
