Process accounting resumed
Process accounting resumed
Process accounting resumed
Process accounting resumed
==================================================================
BUG: KASAN: use-after-free in alloc_branch fs/minix/itree_common.c:92 [inline]
BUG: KASAN: use-after-free in get_block+0xfaa/0x10f0 fs/minix/itree_common.c:191
Write of size 2 at addr ffff888080f0f7b8 by task syz-executor781/7387

CPU: 1 PID: 7387 Comm: syz-executor781 Not tainted 4.14.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x13e/0x194 lib/dump_stack.c:58
 print_address_description.cold+0x7c/0x1e2 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2ae mm/kasan/report.c:393
 alloc_branch fs/minix/itree_common.c:92 [inline]
 get_block+0xfaa/0x10f0 fs/minix/itree_common.c:191
 minix_get_block+0xd6/0x100 fs/minix/inode.c:379
 __block_write_begin_int+0x337/0x1030 fs/buffer.c:2038
 __block_write_begin fs/buffer.c:2088 [inline]
 block_write_begin+0x58/0x260 fs/buffer.c:2147
 minix_write_begin+0x35/0xc0 fs/minix/inode.c:415
 generic_perform_write+0x1c9/0x420 mm/filemap.c:3047
 __generic_file_write_iter+0x227/0x590 mm/filemap.c:3172
 generic_file_write_iter+0x2fa/0x650 mm/filemap.c:3200
 call_write_iter include/linux/fs.h:1778 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x44e/0x630 fs/read_write.c:482
 __kernel_write+0xf5/0x330 fs/read_write.c:501
 do_acct_process+0xb49/0xf60 kernel/acct.c:520
 acct_pin_kill+0x28/0xe0 kernel/acct.c:174
 pin_kill+0x147/0x650 fs/fs_pin.c:50
 acct_on kernel/acct.c:254 [inline]
 SYSC_acct kernel/acct.c:286 [inline]
 SyS_acct+0x528/0x850 kernel/acct.c:273
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x44ba09
RSP: 002b:00007fcb001b8ce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a3
RAX: ffffffffffffffda RBX: 00000000006e39c8 RCX: 000000000044ba09
RDX: 000000000044ba09 RSI: edc86c9e6ad7551b RDI: 0000000020000480
RBP: 00000000006e39c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006e39cc
R13: 00007fffcc728b7f R14: 00007fcb001b99c0 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea000203c3c0 count:0 mapcount:0 mapping:          (null) index:0x1
flags: 0xfffe0000000000()
raw: 00fffe0000000000 0000000000000000 0000000000000001 00000000ffffffff
raw: ffffea000203f3e0 ffffea0002038020 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected
Process accounting resumed

Memory state around the buggy address:
 ffff888080f0f680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888080f0f700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888080f0f780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                        ^
 ffff888080f0f800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888080f0f880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================