==================================================================
BUG: KASAN: slab-out-of-bounds in qrtr_endpoint_post+0xeeb/0x1010 net/qrtr/qrtr.c:462
Read of size 2 at addr ffff88809e5a7508 by task syz-executor201/6796

CPU: 0 PID: 6796 Comm: syz-executor201 Not tainted 5.8.0-rc2-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+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 qrtr_endpoint_post+0xeeb/0x1010 net/qrtr/qrtr.c:462
 qrtr_tun_write_iter+0xf5/0x180 net/qrtr/tun.c:92
 call_write_iter include/linux/fs.h:1907 [inline]
 do_iter_readv_writev+0x567/0x780 fs/read_write.c:694
 do_iter_write+0x188/0x5f0 fs/read_write.c:999
 vfs_writev+0x1aa/0x2e0 fs/read_write.c:1072
 do_pwritev fs/read_write.c:1169 [inline]
 __do_sys_pwritev fs/read_write.c:1216 [inline]
 __se_sys_pwritev fs/read_write.c:1211 [inline]
 __x64_sys_pwritev+0x231/0x310 fs/read_write.c:1211
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4401d9
Code: Bad RIP value.
RSP: 002b:00007ffc466e9768 EFLAGS: 00000246 ORIG_RAX: 0000000000000128
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004401d9
RDX: 0000000000000001 RSI: 0000000020000440 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a60
R13: 0000000000401af0 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 6796:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x17a/0x340 mm/slab.c:3665
 kmalloc include/linux/slab.h:560 [inline]
 kzalloc include/linux/slab.h:669 [inline]
 qrtr_tun_write_iter+0x8a/0x180 net/qrtr/tun.c:83
 call_write_iter include/linux/fs.h:1907 [inline]
 do_iter_readv_writev+0x567/0x780 fs/read_write.c:694
 do_iter_write+0x188/0x5f0 fs/read_write.c:999
 vfs_writev+0x1aa/0x2e0 fs/read_write.c:1072
 do_pwritev fs/read_write.c:1169 [inline]
 __do_sys_pwritev fs/read_write.c:1216 [inline]
 __se_sys_pwritev fs/read_write.c:1211 [inline]
 __x64_sys_pwritev+0x231/0x310 fs/read_write.c:1211
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 4840:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 kasan_set_free_info mm/kasan/common.c:316 [inline]
 __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x103/0x2c0 mm/slab.c:3757
 single_release+0x8c/0xb0 fs/seq_file.c:585
 close_pdeo.part.0+0xdc/0x2e0 fs/proc/inode.c:244
 close_pdeo fs/proc/inode.c:562 [inline]
 proc_reg_release+0x2e9/0x360 fs/proc/inode.c:561
 __fput+0x33c/0x880 fs/file_table.c:281
 task_work_run+0xdd/0x190 kernel/task_work.c:123
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:216 [inline]
 __prepare_exit_to_usermode+0x1e9/0x1f0 arch/x86/entry/common.c:246
 do_syscall_64+0x6c/0xe0 arch/x86/entry/common.c:368
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff88809e5a7500
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 8 bytes inside of
 32-byte region [ffff88809e5a7500, ffff88809e5a7520)
The buggy address belongs to the page:
page:ffffea00027969c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88809e5a7fc1
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002797048 ffffea00027b06c8 ffff8880aa0001c0
raw: ffff88809e5a7fc1 ffff88809e5a7000 0000000100000016 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809e5a7400: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff88809e5a7480: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff88809e5a7500: 04 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
                      ^
 ffff88809e5a7580: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff88809e5a7600: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================