================================================================== BUG: KASAN: use-after-free in __tctx_task_work fs/io_uring.c:2217 [inline] BUG: KASAN: use-after-free in tctx_task_work+0x238/0x280 fs/io_uring.c:2230 Read of size 4 at addr ffff88802178e3f0 by task syz-executor.2/12656 CPU: 1 PID: 12656 Comm: syz-executor.2 Not tainted 5.11.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x125/0x19e lib/dump_stack.c:120 print_address_description+0x5f/0x3a0 mm/kasan/report.c:230 __kasan_report mm/kasan/report.c:397 [inline] kasan_report+0x15e/0x200 mm/kasan/report.c:414 __tctx_task_work fs/io_uring.c:2217 [inline] tctx_task_work+0x238/0x280 fs/io_uring.c:2230 task_work_run+0x146/0x1c0 kernel/task_work.c:140 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0x6e4/0x2380 kernel/exit.c:825 do_group_exit+0x168/0x2d0 kernel/exit.c:922 get_signal+0x1734/0x1ef0 kernel/signal.c:2773 arch_do_signal_or_restart+0x3c/0x610 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0xac/0x1e0 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x48/0x180 kernel/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x465ef9 Code: Unable to access opcode bytes at RIP 0x465ecf. RSP: 002b:00007f80563b5188 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: 0000000000000302 RBX: 000000000056c008 RCX: 0000000000465ef9 RDX: 0000000000000000 RSI: 0000000000000302 RDI: 0000000000000003 RBP: 00000000004bcd1c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008 R13: 00007ffedb23021f R14: 00007f80563b5300 R15: 0000000000022000 Allocated by task 12638: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:400 [inline] ____kasan_kmalloc+0xbd/0xf0 mm/kasan/common.c:428 kasan_kmalloc include/linux/kasan.h:218 [inline] kmem_cache_alloc_trace+0x205/0x300 mm/slub.c:2922 kmalloc include/linux/slab.h:554 [inline] kzalloc include/linux/slab.h:684 [inline] io_ring_ctx_alloc fs/io_uring.c:1316 [inline] io_uring_create fs/io_uring.c:9745 [inline] io_uring_setup fs/io_uring.c:9876 [inline] __do_sys_io_uring_setup fs/io_uring.c:9882 [inline] __se_sys_io_uring_setup+0x368/0x3140 fs/io_uring.c:9879 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 54: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x3d/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:356 ____kasan_slab_free+0xd3/0x110 mm/kasan/common.c:361 kasan_slab_free include/linux/kasan.h:191 [inline] slab_free_hook mm/slub.c:1561 [inline] slab_free_freelist_hook+0xdd/0x1b0 mm/slub.c:1594 slab_free mm/slub.c:3146 [inline] kfree+0xcf/0x2b0 mm/slub.c:4182 process_one_work+0x789/0xfd0 kernel/workqueue.c:2275 worker_thread+0xac1/0x1300 kernel/workqueue.c:2421 kthread+0x39a/0x3c0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Last potentially related work creation: kasan_save_stack+0x27/0x50 mm/kasan/common.c:38 kasan_record_aux_stack+0xcc/0x100 mm/kasan/generic.c:344 insert_work+0x54/0x400 kernel/workqueue.c:1331 __queue_work+0x97f/0xcc0 kernel/workqueue.c:1497 queue_work_on+0xb5/0x100 kernel/workqueue.c:1524 io_uring_release+0x57/0x70 fs/io_uring.c:8895 __fput+0x352/0x7b0 fs/file_table.c:280 task_work_run+0x146/0x1c0 kernel/task_work.c:140 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0x6e4/0x2380 kernel/exit.c:825 do_group_exit+0x168/0x2d0 kernel/exit.c:922 get_signal+0x1734/0x1ef0 kernel/signal.c:2773 arch_do_signal_or_restart+0x3c/0x610 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0xac/0x1e0 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x48/0x180 kernel/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff88802178e000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1008 bytes inside of 4096-byte region [ffff88802178e000, ffff88802178f000) The buggy address belongs to the page: page:00000000f7d94ef1 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21788 head:00000000f7d94ef1 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888011042140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88802178e280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802178e300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802178e380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802178e400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802178e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================