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BUG: KASAN: use-after-free in memset include/linux/string.h:329 [inline]
BUG: KASAN: use-after-free in __ext4_expand_extra_isize.isra.13+0x108/0x1b0 fs/ext4/inode.c:5780
Write of size 65503 at addr ffff8801891a47a0 by task syz-executor4/31761

CPU: 0 PID: 31761 Comm: syz-executor4 Not tainted 4.14.75+ #18
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x11b lib/dump_stack.c:53
 print_address_description+0x60/0x22b mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report.cold.6+0x11b/0x2dd mm/kasan/report.c:409
 memset+0x1f/0x40 mm/kasan/kasan.c:285
 memset include/linux/string.h:329 [inline]
 __ext4_expand_extra_isize.isra.13+0x108/0x1b0 fs/ext4/inode.c:5780
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5832 [inline]
 ext4_mark_inode_dirty+0x46c/0x7e0 fs/ext4/inode.c:5908
 ext4_evict_inode+0x69a/0x1520 fs/ext4/inode.c:282
 evict+0x2cb/0x5f0 fs/inode.c:554
 iput_final fs/inode.c:1516 [inline]
 iput+0x373/0x8e0 fs/inode.c:1543
 dentry_unlink_inode+0x25c/0x310 fs/dcache.c:373
 __dentry_kill+0x31b/0x590 fs/dcache.c:577
 dentry_kill fs/dcache.c:618 [inline]
 dput.part.6+0x4b5/0x710 fs/dcache.c:833
kauditd_printk_skb: 207 callbacks suppressed
audit: type=1400 audit(1539352543.226:8255): avc:  denied  { map } for  pid=24915 comm="udevd" path="/etc/ld.so.cache" dev="sda1" ino=2503 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1
audit: type=1400 audit(1539352543.246:8256): avc:  denied  { map } for  pid=24915 comm="udevd" path="/lib/x86_64-linux-gnu/libgcc_s.so.1" dev="sda1" ino=2665 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1
audit: type=1400 audit(1539352543.246:8257): avc:  denied  { map } for  pid=24915 comm="udevd" path="/lib/x86_64-linux-gnu/libgcc_s.so.1" dev="sda1" ino=2665 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1
EXT4-fs (sda1): EXT4-fs: inode_readahead_blks must be 0 or a power of 2 smaller than 2^31
 dput+0x1b/0x30 fs/dcache.c:797
 __fput+0x42c/0x6f0 fs/file_table.c:228
 task_work_run+0x116/0x190 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x8f8/0x2800 kernel/exit.c:865
 do_group_exit+0x100/0x2e0 kernel/exit.c:968
 get_signal+0x4e5/0x1470 kernel/signal.c:2348
 do_signal+0x8f/0x1660 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0x116/0x150 arch/x86/entry/common.c:159
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:267 [inline]
 do_syscall_64+0x35d/0x4b0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x457519
RSP: 002b:00007fd53b07acf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000072bf08 RCX: 0000000000457519
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000072bf08
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000072bf0c
audit: type=1400 audit(1539352543.496:8258): avc:  denied  { map } for  pid=20824 comm="syz-executor3" path=2F6D656D66643A776CD0C6D26F6D696D655F747970652D7472757374651D202864656C6574656429 dev="tmpfs" ino=118130 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:tmpfs_t:s0 tclass=file permissive=1
audit: type=1400 audit(1539352543.526:8259): avc:  denied  { map } for  pid=20824 comm="syz-executor3" path=2F6D656D66643A776CD0C6D26F6D696D655F747970652D7472757374651D202864656C6574656429 dev="tmpfs" ino=118133 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:tmpfs_t:s0 tclass=file permissive=1
R13: 00007ffc0730ff3f R14: 00007fd53b07b9c0 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea0006246900 count:2 mapcount:0 mapping:ffff8801d9aa8950 index:0x438
flags: 0x4000000000001074(referenced|dirty|lru|active|private)
raw: 4000000000001074 ffff8801d9aa8950 0000000000000438 00000002ffffffff
raw: ffffea00063f46e0 ffffea00063f3ee0 ffff8801933f59d8 ffff8801da81aa80
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff8801da81aa80

Memory state around the buggy address:
 ffff8801891a5f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801891a5f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801891a6000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff8801891a6080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8801891a6100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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