On Thu, 04 Jan 2024 03:33:25 -0800 syzbot <syzbot+fd93e36ced1a43a58f75@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 610a9b8f49fb Linux 6.7-rc8 > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=106d2699e80000 > kernel config: https://syzkaller.appspot.com/x/.config?x=48ca880a5d56f9b1 > dashboard link: https://syzkaller.appspot.com/bug?extid=fd93e36ced1a43a58f75 > compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15f4cc41e80000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14d526ade80000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/b1acb98afcb0/disk-610a9b8f.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/4f7d6503eb8c/vmlinux-610a9b8f.xz > kernel image: https://storage.googleapis.com/syzbot-assets/927f38e505d9/bzImage-610a9b8f.xz > mounted in repro: https://storage.googleapis.com/syzbot-assets/c4f427645c60/mount_0.gz > > The issue was bisected to: > > commit 13d257503c0930010ef9eed78b689cec417ab741 > Author: Shreyansh Chouhan <chouhan.shreyansh630@xxxxxxxxx> > Date: Fri Jul 9 15:29:29 2021 +0000 > > reiserfs: check directory items on read from disk > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1603b8f9e80000 >From the above there's this: testing commit c81cfb6256d90ea5ba4a6fb280ea3b171be4e05c gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 497e79600c6ea11f26483c542ee335e10f144dccb7fe657a67bd32d527271e77 all runs: OK false negative chance: 0.000 # git bisect good c81cfb6256d90ea5ba4a6fb280ea3b171be4e05c Bisecting: 936 revisions left to test after this (roughly 10 steps) [e04480920d1eec9c061841399aa6f35b6f987d8b] Bluetooth: defer cleanup of resources in hci_unregister_dev() testing commit e04480920d1eec9c061841399aa6f35b6f987d8b gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 05fb4fd86182a07a0a9fbfcc25fafd9df57e9d38d1c03a915a6b73410507148c run #0: crashed: BUG: unable to handle kernel paging request in leaf_paste_in_buffer run #1: crashed: BUG: unable to handle kernel NULL pointer dereference in expand_downwards run #2: crashed: INFO: trying to register non-static key in inode_doinit_with_dentry run #3: crashed: BUG: unable to handle kernel paging request in do_epoll_wait run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK run #10: OK run #11: OK run #12: OK run #13: OK run #14: OK run #15: OK run #16: OK run #17: OK run #18: OK run #19: OK representative crash: BUG: unable to handle kernel paging request in leaf_paste_in_buffer, types: [UNKNOWN] # git bisect bad e04480920d1eec9c061841399aa6f35b6f987d8b Bisecting: 456 revisions left to test after this (roughly 9 steps) [1e60cebf82948cfdc9497ea4553bab125587593c] net: let flow have same hash in two directions If the "bad" only crashed 20% of the time, you can not trust any of the "all runs: OK". Not to mention each crash looks to be a separate bug! > final oops: https://syzkaller.appspot.com/x/report.txt?x=1503b8f9e80000 And this is: REISERFS (device loop0): checking transaction log (loop0) REISERFS (device loop0): Using r5 hash to sort names REISERFS (device loop0): using 3.5.x disk format REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage. Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: __schedule+0x13c2/0x13e0 kernel/sched/core.c:5948 Kernel Offset: disabled Rebooting in 86400 seconds.. Which looks like a corrupted (overrun?) stack. Which saying this is a "general protection fault" bug will put us in a wild goose chase. > console output: https://syzkaller.appspot.com/x/log.txt?x=1103b8f9e80000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+fd93e36ced1a43a58f75@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: 13d257503c09 ("reiserfs: check directory items on read from disk") > > general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN > KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] > CPU: 1 PID: 5048 Comm: sshd Not tainted 6.7.0-rc8-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 > RIP: 0010:_compound_head include/linux/page-flags.h:247 [inline] > RIP: 0010:free_swap_cache+0x25/0x3d0 mm/swap_state.c:287 > Code: 0f 1f 44 00 00 66 0f 1f 00 41 54 55 53 48 89 fb e8 90 e9 b2 ff 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 34 03 00 00 4c 8b 63 08 31 ff 4c 89 e5 83 e5 01 > RSP: 0018:ffffc900034df938 EFLAGS: 00010202 > RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff81d3826a > RDX: 0000000000000001 RSI: ffffffff81d37b70 RDI: 0000000000000008 > RBP: 0000000000000005 R08: 0000000000000004 R09: 0000000000000200 > R10: 0000000000000004 R11: 0000000000000001 R12: 0000000000000200 > R13: dffffc0000000000 R14: ffff88807490d010 R15: ffff88807490d008 > FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007ffc22cebe00 CR3: 000000007c973000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > free_pages_and_swap_cache+0x60/0xa0 mm/swap_state.c:315 > tlb_batch_pages_flush+0x9a/0x190 mm/mmu_gather.c:98 > tlb_flush_mmu_free mm/mmu_gather.c:293 [inline] > tlb_flush_mmu mm/mmu_gather.c:300 [inline] > tlb_finish_mmu+0x14b/0x6f0 mm/mmu_gather.c:392 > exit_mmap+0x38b/0xa70 mm/mmap.c:3321 > __mmput+0x12a/0x4d0 kernel/fork.c:1349 > mmput+0x62/0x70 kernel/fork.c:1371 > exit_mm kernel/exit.c:567 [inline] > do_exit+0x9a5/0x2ad0 kernel/exit.c:856 > do_group_exit+0xd4/0x2a0 kernel/exit.c:1018 > get_signal+0x23b5/0x2790 kernel/signal.c:2904 > arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309 > exit_to_user_mode_loop kernel/entry/common.c:168 [inline] > exit_to_user_mode_prepare+0x121/0x240 kernel/entry/common.c:204 > __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] > syscall_exit_to_user_mode+0x1e/0x60 kernel/entry/common.c:296 > do_syscall_64+0x4d/0x110 arch/x86/entry/common.c:89 > entry_SYSCALL_64_after_hwframe+0x63/0x6b > RIP: 0033:0x5623b9f0af8e > Code: Unable to access opcode bytes at 0x5623b9f0af64. > RSP: 002b:00007fff3b36f178 EFLAGS: 00000246 ORIG_RAX: 000000000000010f > RAX: 0000000000000000 RBX: 00000000000668a0 RCX: 00007f85b4f19ad5 > RDX: 00007fff3b36f180 RSI: 00007fff3b36f2b0 RDI: 0000000000000011 > RBP: 00005623bb920260 R08: 0000000000000008 R09: 0000000000000000 > R10: 00007fff3b36f848 R11: 0000000000000246 R12: 00005623b9f8faa4 > R13: 0000000000000001 R14: 00005623b9f903e8 R15: 00007fff3b36f7c8 > </TASK> > Modules linked in: > ---------------- > Code disassembly (best guess): > 0: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) > 5: 66 0f 1f 00 nopw (%rax) > 9: 41 54 push %r12 > b: 55 push %rbp > c: 53 push %rbx > d: 48 89 fb mov %rdi,%rbx > 10: e8 90 e9 b2 ff call 0xffb2e9a5 > 15: 48 8d 7b 08 lea 0x8(%rbx),%rdi > 19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax > 20: fc ff df > 23: 48 89 fa mov %rdi,%rdx > 26: 48 c1 ea 03 shr $0x3,%rdx > * 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction > 2e: 0f 85 34 03 00 00 jne 0x368 > 34: 4c 8b 63 08 mov 0x8(%rbx),%r12 > 38: 31 ff xor %edi,%edi > 3a: 4c 89 e5 mov %r12,%rbp > 3d: 83 e5 01 and $0x1,%ebp > > > --- > This report is generated by a bot. It may contain errors. I would say it does. Anyway, it is possibly a reiserfs bug that's using too much stack. But it would be nice if these bot reports had a bit better bisecting algorithm. -- Steve > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > For information about bisection process see: https://goo.gl/tpsmEJ#bisection > > 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: > #syz set subsystems: new-subsystem > (See the list of subsystem names on the web dashboard) > > 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