[syzbot] [fs?] general protection fault in iter_file_splice_write

From: syzbot
Date: Mon May 20 2024 - 04:06:52 EST


Hello,

syzbot found the following issue on:

HEAD commit: 33e02dc69afb Merge tag 'sound-6.10-rc1' of git://git.kerne..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13ad18d0980000
kernel config: https://syzkaller.appspot.com/x/.config?x=25544a2faf4bae65
dashboard link: https://syzkaller.appspot.com/bug?extid=d2125fcb6aa8c4276fd2
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=1526a8dc980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14f53ae4980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-33e02dc6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/573c88ac3233/vmlinux-33e02dc6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/760a52b9a00a/bzImage-33e02dc6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d2125fcb6aa8c4276fd2@xxxxxxxxxxxxxxxxxxxxxxxxx

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 3 PID: 5196 Comm: syz-executor259 Not tainted 6.9.0-syzkaller-07370-g33e02dc69afb #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:pipe_buf_release include/linux/pipe_fs_i.h:219 [inline]
RIP: 0010:iter_file_splice_write+0xa24/0x10b0 fs/splice.c:759
Code: 00 48 89 fa 48 c1 ea 03 80 3c 1a 00 0f 85 b1 04 00 00 4d 8b 65 10 49 c7 45 10 00 00 00 00 49 8d 7c 24 08 48 89 fa 48 c1 ea 03 <80> 3c 1a 00 0f 85 1a 05 00 00 49 8b 54 24 08 4c 89 ee 4c 89 ff 83
RSP: 0018:ffffc900031b7930 EFLAGS: 00010202
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffffff8209a1a8
RDX: 0000000000000001 RSI: ffffffff8209a06c RDI: 0000000000000008
RBP: 000000000000003d R08: 0000000000000006 R09: 0000000000000000
R10: 7fffffffffffefff R11: 0000000000000001 R12: 0000000000000000
R13: ffff888026d5a208 R14: 7fffffffffffefff R15: ffff88801e5c5800
FS: 00007f78cdfc16c0(0000) GS:ffff88806b300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f78ce0454d0 CR3: 0000000019dc8000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
do_splice_from fs/splice.c:941 [inline]
direct_splice_actor+0x19b/0x6d0 fs/splice.c:1164
splice_direct_to_actor+0x346/0xa40 fs/splice.c:1108
do_splice_direct_actor fs/splice.c:1207 [inline]
do_splice_direct+0x17e/0x250 fs/splice.c:1233
do_sendfile+0xaa8/0xdb0 fs/read_write.c:1295
__do_sys_sendfile64 fs/read_write.c:1362 [inline]
__se_sys_sendfile64 fs/read_write.c:1348 [inline]
__x64_sys_sendfile64+0x1da/0x220 fs/read_write.c:1348
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f78ce009d09
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 18 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:00007f78cdfc1168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f78ce091328 RCX: 00007f78ce009d09
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000004
RBP: 00007f78ce091320 R08: 00007f78cdfc16c0 R09: 0000000000000000
R10: 0000000100000000 R11: 0000000000000246 R12: 00007f78ce09132c
R13: 0000000000000006 R14: 00007ffe98369ff0 R15: 00007ffe9836a0d8
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:pipe_buf_release include/linux/pipe_fs_i.h:219 [inline]
RIP: 0010:iter_file_splice_write+0xa24/0x10b0 fs/splice.c:759
Code: 00 48 89 fa 48 c1 ea 03 80 3c 1a 00 0f 85 b1 04 00 00 4d 8b 65 10 49 c7 45 10 00 00 00 00 49 8d 7c 24 08 48 89 fa 48 c1 ea 03 <80> 3c 1a 00 0f 85 1a 05 00 00 49 8b 54 24 08 4c 89 ee 4c 89 ff 83
RSP: 0018:ffffc900031b7930 EFLAGS: 00010202
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffffff8209a1a8
RDX: 0000000000000001 RSI: ffffffff8209a06c RDI: 0000000000000008
RBP: 000000000000003d R08: 0000000000000006 R09: 0000000000000000
R10: 7fffffffffffefff R11: 0000000000000001 R12: 0000000000000000
R13: ffff888026d5a208 R14: 7fffffffffffefff R15: ffff88801e5c5800
FS: 00007f78cdfc16c0(0000) GS:ffff88806b200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f78ce05d0d8 CR3: 0000000019dc8000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 00 48 89 add %cl,-0x77(%rax)
3: fa cli
4: 48 c1 ea 03 shr $0x3,%rdx
8: 80 3c 1a 00 cmpb $0x0,(%rdx,%rbx,1)
c: 0f 85 b1 04 00 00 jne 0x4c3
12: 4d 8b 65 10 mov 0x10(%r13),%r12
16: 49 c7 45 10 00 00 00 movq $0x0,0x10(%r13)
1d: 00
1e: 49 8d 7c 24 08 lea 0x8(%r12),%rdi
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 80 3c 1a 00 cmpb $0x0,(%rdx,%rbx,1) <-- trapping instruction
2e: 0f 85 1a 05 00 00 jne 0x54e
34: 49 8b 54 24 08 mov 0x8(%r12),%rdx
39: 4c 89 ee mov %r13,%rsi
3c: 4c 89 ff mov %r15,%rdi
3f: 83 .byte 0x83


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