================================================================== BUG: KASAN: use-after-free in arch_atomic_read arch/x86/include/asm/atomic.h:31 [inline] BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:28 [inline] BUG: KASAN: use-after-free in blk_cgroup_congested include/linux/blk-cgroup.h:288 [inline] BUG: KASAN: use-after-free in cgroup_throttle_swaprate+0x2c5/0x4f0 mm/swapfile.c:3798 Read of size 4 at addr ffff888098088d80 by task syz-executor.4/8324 CPU: 1 PID: 8324 Comm: syz-executor.4 Not tainted 5.8.0-rc5-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+0x1f0/0x31e lib/dump_stack.c:118 print_address_description+0x66/0x5a0 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report+0x132/0x1d0 mm/kasan/report.c:530 arch_atomic_read arch/x86/include/asm/atomic.h:31 [inline] atomic_read include/asm-generic/atomic-instrumented.h:28 [inline] blk_cgroup_congested include/linux/blk-cgroup.h:288 [inline] cgroup_throttle_swaprate+0x2c5/0x4f0 mm/swapfile.c:3798 shmem_add_to_page_cache+0xaec/0x1800 mm/shmem.c:635 shmem_getpage_gfp+0x9a3/0x2c60 mm/shmem.c:1857 shmem_getpage mm/shmem.c:153 [inline] shmem_file_read_iter+0x266/0xb60 mm/shmem.c:2536 call_read_iter include/linux/fs.h:1902 [inline] generic_file_splice_read+0x3c4/0x660 fs/splice.c:312 do_splice_to fs/splice.c:870 [inline] splice_direct_to_actor+0x3bd/0xb60 fs/splice.c:950 do_splice_direct+0x201/0x340 fs/splice.c:1059 do_sendfile+0x809/0xfe0 fs/read_write.c:1540 __do_sys_sendfile64 fs/read_write.c:1601 [inline] __se_sys_sendfile64 fs/read_write.c:1587 [inline] __x64_sys_sendfile64+0x164/0x1a0 fs/read_write.c:1587 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cba9 Code: Bad RIP value. RSP: 002b:00007f300f688c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00000000004fe820 RCX: 000000000045cba9 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000007 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000eefffdef R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000926 R14: 00000000004cbfac R15: 00007f300f6896d4 Allocated by task 1: save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0x103/0x140 mm/kasan/common.c:494 kmem_cache_alloc_trace+0x234/0x300 mm/slab.c:3551 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:669 [inline] cgroup1_root_to_use kernel/cgroup/cgroup-v1.c:1183 [inline] cgroup1_get_tree+0x747/0xae0 kernel/cgroup/cgroup-v1.c:1207 vfs_get_tree+0x88/0x270 fs/super.c:1547 do_new_mount fs/namespace.c:2874 [inline] do_mount+0x17e8/0x2900 fs/namespace.c:3199 __do_sys_mount fs/namespace.c:3409 [inline] __se_sys_mount+0xd3/0x100 fs/namespace.c:3386 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 3850: save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x220 mm/slab.c:3757 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 The buggy address belongs to the object at ffff888098088000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 3456 bytes inside of 8192-byte region [ffff888098088000, ffff88809808a000) The buggy address belongs to the page: page:ffffea0002602200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 head:ffffea0002602200 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea0002601908 ffffea0002602c08 ffff8880aa4021c0 raw: 0000000000000000 ffff888098088000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888098088c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888098088d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888098088d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888098088e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888098088e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================