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BUG: KASAN: slab-out-of-bounds in iov_iter_alignment+0x6a1/0x7b0 lib/iov_iter.c:1225
Read of size 4 at addr ffff8880a8ac25d4 by task syz-executor.3/18128

CPU: 0 PID: 18128 Comm: syz-executor.3 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 print_address_description+0x75/0x5c0 mm/kasan/report.c:374
 __kasan_report+0x14b/0x1c0 mm/kasan/report.c:506
 kasan_report+0x26/0x50 mm/kasan/common.c:634
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131
 iov_iter_alignment+0x6a1/0x7b0 lib/iov_iter.c:1225
 __blkdev_direct_IO+0x127/0x10c0 fs/block_dev.c:352
 blkdev_direct_IO+0xbe/0xd0 fs/block_dev.c:476
 generic_file_read_iter+0x2bf/0x450 mm/filemap.c:2303
 blkdev_read_iter+0x12e/0x140 fs/block_dev.c:2039
 do_iter_readv_writev+0x651/0x8e0 include/linux/fs.h:1889
 do_iter_read+0x182/0x5b0 fs/read_write.c:933
 vfs_readv fs/read_write.c:997 [inline]
 do_preadv+0x178/0x290 fs/read_write.c:1089
 __do_sys_preadv fs/read_write.c:1139 [inline]
 __se_sys_preadv fs/read_write.c:1134 [inline]
 __x64_sys_preadv+0x9e/0xb0 fs/read_write.c:1134
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a679
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f793bfbec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045a679
RDX: 0000000000000009 RSI: 0000000020000040 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f793bfbf6d4
R13: 00000000004c80e9 R14: 00000000004de8d0 R15: 00000000ffffffff

Allocated by task 18128:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc+0x11c/0x1b0 mm/kasan/common.c:510
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:524
 __do_kmalloc mm/slab.c:3655 [inline]
 __kmalloc+0x254/0x340 mm/slab.c:3664
 kmalloc_array+0x2f/0x50 include/linux/slab.h:618
 rw_copy_check_uvector+0x96/0x360 fs/read_write.c:792
 import_iovec+0x8c/0x2a0 lib/iov_iter.c:1678
 vfs_readv fs/read_write.c:995 [inline]
 do_preadv+0x146/0x290 fs/read_write.c:1089
 __do_sys_preadv fs/read_write.c:1139 [inline]
 __se_sys_preadv fs/read_write.c:1134 [inline]
 __x64_sys_preadv+0x9e/0xb0 fs/read_write.c:1134
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 17504:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 kasan_set_free_info mm/kasan/common.c:332 [inline]
 __kasan_slab_free+0x12a/0x1e0 mm/kasan/common.c:471
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:480
 __cache_free mm/slab.c:3425 [inline]
 kfree+0x115/0x200 mm/slab.c:3756
 security_cred_free+0xcd/0x100 security/security.c:1548
 put_cred_rcu+0xcf/0x360 kernel/cred.c:114
 __put_cred+0x154/0x210 kernel/cred.c:148
 put_cred include/linux/cred.h:287 [inline]
 do_faccessat+0x604/0x770 fs/open.c:439
 __do_sys_access fs/open.c:450 [inline]
 __se_sys_access fs/open.c:448 [inline]
 __x64_sys_access+0x5f/0x70 fs/open.c:448
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880a8ac2500
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 20 bytes to the right of
 192-byte region [ffff8880a8ac2500, ffff8880a8ac25c0)
The buggy address belongs to the page:
page:ffffea0002a2b080 refcount:1 mapcount:0 mapping:ffff8880aa400000 index:0xffff8880a8ac2f00
raw: 00fffe0000000200 ffffea0002a5e188 ffffea0002617a88 ffff8880aa400000
raw: ffff8880a8ac2f00 ffff8880a8ac2000 000000010000000f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a8ac2480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8880a8ac2500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880a8ac2580: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                 ^
 ffff8880a8ac2600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a8ac2680: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
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