On Mon, Oct 14, 2024 at 10:58 AM syzbot <syzbot+aaf95b6e8fc9d906d8a7@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: d61a00525464 Add linux-next specific files for 20241011 > git tree: linux-next > console+strace: https://syzkaller.appspot.com/x/log.txt?x=1688fb27980000 > kernel config: https://syzkaller.appspot.com/x/.config?x=8554528c7f4bf3fb > dashboard link: https://syzkaller.appspot.com/bug?extid=aaf95b6e8fc9d906d8a7 > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10d5705f980000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1188fb27980000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/f615720e9964/disk-d61a0052.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/c4a45c7583c6/vmlinux-d61a0052.xz > kernel image: https://storage.googleapis.com/syzbot-assets/d767ab86d0d0/bzImage-d61a0052.xz > > The issue was bisected to: > > commit 181d71062eef699385d92b92f8ad3cbf03e61267 > Author: Amir Goldstein <amir73il@xxxxxxxxx> > Date: Mon Oct 7 13:22:29 2024 +0000 > > ovl: allocate a container struct ovl_file for ovl private context > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11c41440580000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=13c41440580000 > console output: https://syzkaller.appspot.com/x/log.txt?x=15c41440580000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+aaf95b6e8fc9d906d8a7@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: 181d71062eef ("ovl: allocate a container struct ovl_file for ovl private context") > > Oops: general protection fault, probably for non-canonical address 0xdffffc000000000d: 0000 [#1] PREEMPT SMP KASAN PTI > KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f] > CPU: 1 UID: 0 PID: 5235 Comm: syz-executor410 Not tainted 6.12.0-rc2-next-20241011-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 > RIP: 0010:file_inode include/linux/fs.h:1124 [inline] > RIP: 0010:ovl_is_real_file fs/overlayfs/file.c:100 [inline] > RIP: 0010:ovl_real_file_path+0xa5/0x2e0 fs/overlayfs/file.c:118 > Code: 03 4d 89 f7 42 80 3c 30 00 74 08 4c 89 ef e8 22 1e e0 fe 4c 89 64 24 10 49 8b 45 00 49 89 c4 4c 8d 70 68 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 fc 1d e0 fe 49 8b 1e 48 83 c5 68 > RSP: 0018:ffffc90002dcfb28 EFLAGS: 00010202 > RAX: 000000000000000d RBX: 1ffff920005b9f79 RCX: ffff88801efa5a00 > RDX: 0000000000000000 RSI: ffffc90002dcfbc0 RDI: ffff888031c9bc00 > RBP: ffff88807eb938f8 R08: ffffffff831d82d9 R09: 0000000000000000 > R10: ffffc90002dcfae0 R11: fffff520005b9f5e R12: 0000000000000000 > R13: ffff888078c80000 R14: 0000000000000068 R15: dffffc0000000000 > FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000020001740 CR3: 000000000e736000 CR4: 00000000003526f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > ovl_real_file+0x186/0x210 fs/overlayfs/file.c:176 > ovl_flush+0x22/0x140 fs/overlayfs/file.c:620 > filp_flush+0xb7/0x160 fs/open.c:1527 > filp_close+0x1e/0x40 fs/open.c:1540 > close_files fs/file.c:508 [inline] > put_files_struct+0x198/0x310 fs/file.c:523 > do_exit+0xa10/0x28e0 kernel/exit.c:933 > do_group_exit+0x207/0x2c0 kernel/exit.c:1087 > __do_sys_exit_group kernel/exit.c:1098 [inline] > __se_sys_exit_group kernel/exit.c:1096 [inline] > __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096 > x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232 > 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: 0033:0x7fbb4c5e7739 > Code: Unable to access opcode bytes at 0x7fbb4c5e770f. > RSP: 002b:00007fff9c70aac8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbb4c5e7739 > RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 > RBP: 00007fbb4c662290 R08: ffffffffffffffb8 R09: 00007fbb4c5b5e50 > R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbb4c662290 > R13: 0000000000000000 R14: 00007fbb4c662ce0 R15: 00007fbb4c5b62a0 > </TASK> > Modules linked in: > ---[ end trace 0000000000000000 ]--- > RIP: 0010:file_inode include/linux/fs.h:1124 [inline] > RIP: 0010:ovl_is_real_file fs/overlayfs/file.c:100 [inline] > RIP: 0010:ovl_real_file_path+0xa5/0x2e0 fs/overlayfs/file.c:118 > Code: 03 4d 89 f7 42 80 3c 30 00 74 08 4c 89 ef e8 22 1e e0 fe 4c 89 64 24 10 49 8b 45 00 49 89 c4 4c 8d 70 68 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 fc 1d e0 fe 49 8b 1e 48 83 c5 68 > RSP: 0018:ffffc90002dcfb28 EFLAGS: 00010202 > RAX: 000000000000000d RBX: 1ffff920005b9f79 RCX: ffff88801efa5a00 > RDX: 0000000000000000 RSI: ffffc90002dcfbc0 RDI: ffff888031c9bc00 > RBP: ffff88807eb938f8 R08: ffffffff831d82d9 R09: 0000000000000000 > R10: ffffc90002dcfae0 R11: fffff520005b9f5e R12: 0000000000000000 > R13: ffff888078c80000 R14: 0000000000000068 R15: dffffc0000000000 > FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000020001740 CR3: 000000000e736000 CR4: 00000000003526f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > ---------------- > Code disassembly (best guess): > 0: 03 4d 89 add -0x77(%rbp),%ecx > 3: f7 42 80 3c 30 00 74 testl $0x7400303c,-0x80(%rdx) > a: 08 4c 89 ef or %cl,-0x11(%rcx,%rcx,4) > e: e8 22 1e e0 fe call 0xfee01e35 > 13: 4c 89 64 24 10 mov %r12,0x10(%rsp) > 18: 49 8b 45 00 mov 0x0(%r13),%rax > 1c: 49 89 c4 mov %rax,%r12 > 1f: 4c 8d 70 68 lea 0x68(%rax),%r14 > 23: 4c 89 f0 mov %r14,%rax > 26: 48 c1 e8 03 shr $0x3,%rax > * 2a: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) <-- trapping instruction > 2f: 74 08 je 0x39 > 31: 4c 89 f7 mov %r14,%rdi > 34: e8 fc 1d e0 fe call 0xfee01e35 > 39: 49 8b 1e mov (%r14),%rbx > 3c: 48 83 c5 68 add $0x68,%rbp > > OOPS broke O_TMPFILE. #syz test: https://github.com/amir73il/linux ovl_real_file Thanks, Amir.
