[syzbot] WARNING in is_valid_gup_args

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 49a8133221c7 Add linux-next specific files for 20230207
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=15016013480000
kernel config: https://syzkaller.appspot.com/x/.config?x=3691b32dd4410e01
dashboard link: https://syzkaller.appspot.com/bug?extid=1f0c9407f4d20f7488b9
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6277c699d71e/disk-49a81332.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cbef27c2f238/vmlinux-49a81332.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7c0c68d93ac8/bzImage-49a81332.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1f0c94...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 11452 at mm/gup.c:2121 is_valid_gup_args+0x1d8/0x230 mm/gup.c:2121
Modules linked in:
CPU: 1 PID: 11452 Comm: syz-executor.0 Not tainted 6.2.0-rc7-next-20230207-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
RIP: 0010:is_valid_gup_args+0x1d8/0x230 mm/gup.c:2121
Code: c7 ff 48 83 3c 24 00 0f 85 7a ff ff ff e8 10 3a c7 ff 0f 0b 45 31 e4 eb cd e8 04 3a c7 ff 0f 0b 45 31 e4 eb c1 e8 f8 39 c7 ff <0f> 0b 45 31 e4 eb b5 e8 ec 39 c7 ff 0f 0b 45 31 e4 eb a9 e8 e0 39
RSP: 0018:ffffc900091f72c0 EFLAGS: 00010212
RAX: 000000000000165e RBX: 0000000000040000 RCX: ffffc90003dc1000
RDX: 0000000000040000 RSI: ffffffff81bd3248 RDI: 0000000000000005
RBP: ffffc900091f7320 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000040000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000040000 R15: 0000000000040000
FS: 00007f31c3ca4700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31624000 CR3: 0000000027a30000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
pin_user_pages_fast+0x83/0x100 mm/gup.c:3089
iov_iter_extract_user_pages lib/iov_iter.c:2160 [inline]
iov_iter_extract_pages+0x2b9/0x1e20 lib/iov_iter.c:2229
__bio_iov_iter_get_pages block/bio.c:1267 [inline]
bio_iov_iter_get_pages block/bio.c:1340 [inline]
bio_iov_iter_get_pages+0x354/0x1580 block/bio.c:1327
iomap_dio_bio_iter+0x830/0x1440 fs/iomap/direct-io.c:323
iomap_dio_iter fs/iomap/direct-io.c:436 [inline]
__iomap_dio_rw+0xd81/0x1d80 fs/iomap/direct-io.c:594
iomap_dio_rw+0x40/0xa0 fs/iomap/direct-io.c:682
ext4_dio_write_iter fs/ext4/file.c:587 [inline]
ext4_file_write_iter+0x1053/0x1710 fs/ext4/file.c:698
call_write_iter include/linux/fs.h:1851 [inline]
do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:735
do_iter_write+0x182/0x700 fs/read_write.c:861
vfs_writev+0x1aa/0x670 fs/read_write.c:934
do_pwritev+0x1b6/0x270 fs/read_write.c:1031
__do_sys_pwritev2 fs/read_write.c:1090 [inline]
__se_sys_pwritev2 fs/read_write.c:1081 [inline]
__x64_sys_pwritev2+0xef/0x150 fs/read_write.c:1081
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: 0033:0x7f31c2e8c0c9
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:00007f31c3ca4168 EFLAGS: 00000246 ORIG_RAX: 0000000000000148
RAX: ffffffffffffffda RBX: 00007f31c2fabf80 RCX: 00007f31c2e8c0c9
RDX: 0000000000000001 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 00007f31c2ee7ae9 R08: 0000000000000000 R09: 0000000000000003
R10: 0000000000001400 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff54ef18ef R14: 00007f31c3ca4300 R15: 0000000000022000
</TASK>


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[Hillf Danton]

On Mate: Mon, 06 Feb 2023 22:23:56 -0800

Quick fix like the diff below can be test when a reproducer is available.

--- x/lib/iov_iter.c
+++ y/lib/iov_iter.c
@@ -2140,7 +2140,7 @@ static ssize_t iov_iter_extract_user_pag
size_t *offset0)
{
unsigned long addr;
- unsigned int gup_flags = FOLL_PIN;
+ unsigned int gup_flags = 0;
size_t offset;
int res;

[syzbot]

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