[fs?] general protection fault in do_iter_read

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 011eb7443621 Add linux-next specific files for 20230327
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=166fa139c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=8ba12b2f4a1ff93d
dashboard link: https://syzkaller.appspot.com/bug?extid=a56a8f33917c9638e22e
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
CC: [bra...@kernel.org linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/513e6a2dc8e5/disk-011eb744.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e1b8a9eee1af/vmlinux-011eb744.xz
kernel image: https://storage.googleapis.com/syzbot-assets/970a4a7123ab/bzImage-011eb744.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a56a8f...@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc00040002c8: 0000 [#1] PREEMPT SMP KASAN
KASAN: probably user-memory-access in range [0x0000000020001640-0x0000000020001647]
CPU: 1 PID: 6644 Comm: syz-executor.0 Not tainted 6.3.0-rc3-next-20230327-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
RIP: 0010:iov_iter_iovec include/linux/uio.h:137 [inline]
RIP: 0010:do_loop_readv_writev fs/read_write.c:752 [inline]
RIP: 0010:do_loop_readv_writev fs/read_write.c:743 [inline]
RIP: 0010:do_iter_read+0x48b/0x750 fs/read_write.c:798
Code: 00 0f 85 3f 02 00 00 4d 8b 75 28 e8 7f ff 9e ff 48 8b 44 24 20 80 38 00 0f 85 0a 02 00 00 49 8b 6c 24 18 48 89 ea 48 c1 ea 03 <42> 80 3c 3a 00 0f 85 e6 01 00 00 48 8b 44 24 28 48 8b 75 00 80 38
RSP: 0018:ffffc90005c37c78 EFLAGS: 00010202
RAX: fffff52000b86faf RBX: 0000000000000094 RCX: ffffc90005499000
RDX: 00000000040002c8 RSI: ffffffff81e3d7d1 RDI: 0000000000000007
RBP: 0000000020001640 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000094 R11: 0000000000000000 R12: ffffc90005c37d60
R13: ffff88807be48f00 R14: ffffffff8a5e4620 R15: dffffc0000000000
FS: 00007f2249e38700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f31265821b8 CR3: 000000002acb9000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
vfs_readv+0xe5/0x150 fs/read_write.c:916
do_preadv fs/read_write.c:1008 [inline]
__do_sys_preadv fs/read_write.c:1058 [inline]
__se_sys_preadv fs/read_write.c:1053 [inline]
__x64_sys_preadv+0x22f/0x310 fs/read_write.c:1053
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f224908c0f9
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:00007f2249e38168 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00007f22491ac050 RCX: 00007f224908c0f9
RDX: 0000000000000001 RSI: 0000000020000140 RDI: 0000000000000005
RBP: 00007f22490e7b39 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000002014a R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff27194e5f R14: 00007f2249e38300 R15: 0000000000022000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:iov_iter_iovec include/linux/uio.h:137 [inline]
RIP: 0010:do_loop_readv_writev fs/read_write.c:752 [inline]
RIP: 0010:do_loop_readv_writev fs/read_write.c:743 [inline]
RIP: 0010:do_iter_read+0x48b/0x750 fs/read_write.c:798
Code: 00 0f 85 3f 02 00 00 4d 8b 75 28 e8 7f ff 9e ff 48 8b 44 24 20 80 38 00 0f 85 0a 02 00 00 49 8b 6c 24 18 48 89 ea 48 c1 ea 03 <42> 80 3c 3a 00 0f 85 e6 01 00 00 48 8b 44 24 28 48 8b 75 00 80 38
RSP: 0018:ffffc90005c37c78 EFLAGS: 00010202
RAX: fffff52000b86faf RBX: 0000000000000094 RCX: ffffc90005499000
RDX: 00000000040002c8 RSI: ffffffff81e3d7d1 RDI: 0000000000000007
RBP: 0000000020001640 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000094 R11: 0000000000000000 R12: ffffc90005c37d60
R13: ffff88807be48f00 R14: ffffffff8a5e4620 R15: dffffc0000000000
FS: 00007f2249e38700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3332f000 CR3: 000000002acb9000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 00 0f add %cl,(%rdi)
2: 85 3f test %edi,(%rdi)
4: 02 00 add (%rax),%al
6: 00 4d 8b add %cl,-0x75(%rbp)
9: 75 28 jne 0x33
b: e8 7f ff 9e ff callq 0xff9eff8f
10: 48 8b 44 24 20 mov 0x20(%rsp),%rax
15: 80 38 00 cmpb $0x0,(%rax)
18: 0f 85 0a 02 00 00 jne 0x228
1e: 49 8b 6c 24 18 mov 0x18(%r12),%rbp
23: 48 89 ea mov %rbp,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 42 80 3c 3a 00 cmpb $0x0,(%rdx,%r15,1) <-- trapping instruction
2f: 0f 85 e6 01 00 00 jne 0x21b
35: 48 8b 44 24 28 mov 0x28(%rsp),%rax
3a: 48 8b 75 00 mov 0x0(%rbp),%rsi
3e: 80 .byte 0x80
3f: 38 .byte 0x38


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.