================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline] BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline] BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:182 [inline] BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:239 [inline] BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:256 [inline] BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:760 [inline] BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x64/0x25c net/bluetooth/sco.c:88 Write of size 4 at addr ffff0000dc114080 by task kworker/1:25/25330 CPU: 1 PID: 25330 Comm: kworker/1:25 Not tainted 6.8.0-rc7-syzkaller-g707081b61156 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: events sco_sock_timeout Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [inline] print_report+0x178/0x518 mm/kasan/report.c:488 kasan_report+0xd8/0x138 mm/kasan/report.c:601 kasan_check_range+0x254/0x294 mm/kasan/generic.c:189 __kasan_check_write+0x20/0x30 mm/kasan/shadow.c:37 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline] __refcount_add include/linux/refcount.h:182 [inline] __refcount_inc include/linux/refcount.h:239 [inline] refcount_inc include/linux/refcount.h:256 [inline] sock_hold include/net/sock.h:760 [inline] sco_sock_timeout+0x64/0x25c net/bluetooth/sco.c:88 process_one_work+0x694/0x1204 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x938/0xef4 kernel/workqueue.c:2787 kthread+0x288/0x310 kernel/kthread.c:388 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 Allocated by task 11099: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:575 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:338 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3813 [inline] slab_alloc_node mm/slub.c:3860 [inline] kmem_cache_alloc+0x1dc/0x488 mm/slub.c:3867 getname_flags+0xd0/0x48c fs/namei.c:140 __se_sys_unlinkat fs/namei.c:4438 [inline] __arm64_sys_unlinkat+0xb4/0xfc fs/namei.c:4438 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 Freed by task 11099: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_free_info+0x54/0x6c mm/kasan/generic.c:589 poison_slab_object+0x124/0x18c mm/kasan/common.c:240 __kasan_slab_free+0x3c/0x70 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2121 [inline] slab_free mm/slub.c:4299 [inline] kmem_cache_free+0x15c/0x3d4 mm/slub.c:4363 putname+0x11c/0x180 fs/namei.c:274 do_rmdir+0x63c/0x720 fs/namei.c:4281 __do_sys_unlinkat fs/namei.c:4444 [inline] __se_sys_unlinkat fs/namei.c:4438 [inline] __arm64_sys_unlinkat+0xe0/0xfc fs/namei.c:4438 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 The buggy address belongs to the object at ffff0000dc113300 which belongs to the cache names_cache of size 4096 The buggy address is located 3456 bytes inside of freed 4096-byte region [ffff0000dc113300, ffff0000dc114300) The buggy address belongs to the physical page: page:00000000d3aa2459 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11c110 head:00000000d3aa2459 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0x5ffc00000000840(slab|head|node=0|zone=2|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 05ffc00000000840 ffff0000c180e8c0 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000dc113f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000dc114000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000dc114080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000dc114100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000dc114180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 25330 at lib/refcount.c:25 refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25 Modules linked in: CPU: 1 PID: 25330 Comm: kworker/1:25 Tainted: G B 6.8.0-rc7-syzkaller-g707081b61156 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: events sco_sock_timeout pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25 lr : refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25 sp : ffff800097f47af0 x29: ffff800097f47af0 x28: 1fffe00018c33b8a x27: dfff800000000000 x26: ffff0000c1084408 x25: ffff0000c619dc50 x24: ffff0001b4035700 x23: dfff800000000000 x22: 0000000000000000 x21: 0000000000000002 x20: ffff0000dc114080 x19: ffff800091cc2000 x18: ffff800097f477e0 x17: 0000000000000000 x16: ffff80008aca6b80 x15: 0000000000000001 x14: 1ffff00012fe8e78 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000003 x10: 0000000000ff0100 x9 : 8116f52ea144d000 x8 : 8116f52ea144d000 x7 : fffffffffffe0b98 x6 : fffffffffffe0b60 x5 : ffff800097f473d8 x4 : ffff80008ed5d9a8 x3 : ffff80008036f0d8 x2 : 0000000000000001 x1 : 0000000000000001 x0 : 0000000000000000 Call trace: refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25 __refcount_inc include/linux/refcount.h:239 [inline] refcount_inc include/linux/refcount.h:256 [inline] sock_hold include/net/sock.h:760 [inline] sco_sock_timeout+0x19c/0x25c net/bluetooth/sco.c:88 process_one_work+0x694/0x1204 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x938/0xef4 kernel/workqueue.c:2787 kthread+0x288/0x310 kernel/kthread.c:388 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 irq event stamp: 212375 hardirqs last enabled at (212375): [] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:85 [inline] hardirqs last enabled at (212375): [] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:95 hardirqs last disabled at (212374): [] __do_softirq+0x958/0xce4 kernel/softirq.c:569 softirqs last enabled at (211872): [] softirq_handle_end kernel/softirq.c:399 [inline] softirqs last enabled at (211872): [] __do_softirq+0xac8/0xce4 kernel/softirq.c:582 softirqs last disabled at (211845): [] ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:81 ---[ end trace 0000000000000000 ]--- Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Mem abort info: ESR = 0x0000000086000004 EC = 0x21: IABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x04: level 0 translation fault user pgtable: 4k pages, 48-bit VAs, pgdp=000000010b523000 [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 Internal error: Oops: 0000000086000004 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 25330 Comm: kworker/1:25 Tainted: G B W 6.8.0-rc7-syzkaller-g707081b61156 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: events sco_sock_timeout pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : 0x0 lr : sco_sock_timeout+0xf4/0x25c net/bluetooth/sco.c:98 sp : ffff800097f47b20 x29: ffff800097f47b20 x28: 1fffe00018c33b8a x27: dfff800000000000 x26: ffff0000c1084408 x25: ffff0000c619dc50 x24: ffff0001b4035700 x23: dfff800000000000 x22: 0000000000000000 x21: ffff0000c619dc08 x20: ffff0000dc114000 x19: ffff0000dc114080 x18: 1fffe00036804396 x17: ffff80008ec9d000 x16: ffff8000809fd6d8 x15: ffff60001b822813 x14: 1fffe0001b822813 x13: 00000000000000fb x12: ffffffffffffffff x11: ffff800097f3ffff x10: 0000000000ff0100 x9 : ffff800093486880 x8 : 0000000000000000 x7 : 1fffe00036804397 x6 : ffff800088eaf8bc x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff800089fa2f38 x2 : 0000000000000000 x1 : 0000000000000008 x0 : ffff0000dc114000 Call trace: 0x0 process_one_work+0x694/0x1204 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x938/0xef4 kernel/workqueue.c:2787 kthread+0x288/0x310 kernel/kthread.c:388 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 Code: ???????? ???????? ???????? ???????? (????????) ---[ end trace 0000000000000000 ]---