================================================================== BUG: KFENCE: use-after-free read in arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] BUG: KFENCE: use-after-free read in raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] BUG: KFENCE: use-after-free read in atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] BUG: KFENCE: use-after-free read in refcount_read include/linux/refcount.h:136 [inline] BUG: KFENCE: use-after-free read in skb_unref include/linux/skbuff.h:1228 [inline] BUG: KFENCE: use-after-free read in __sk_skb_reason_drop net/core/skbuff.c:1211 [inline] BUG: KFENCE: use-after-free read in sk_skb_reason_drop+0x58/0x3d0 net/core/skbuff.c:1239 Use-after-free read at 0xffff88823bdda0e4 (in kfence-#236): arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] refcount_read include/linux/refcount.h:136 [inline] skb_unref include/linux/skbuff.h:1228 [inline] __sk_skb_reason_drop net/core/skbuff.c:1211 [inline] sk_skb_reason_drop+0x58/0x3d0 net/core/skbuff.c:1239 kfree_skb_reason include/linux/skbuff.h:1260 [inline] kfree_skb include/linux/skbuff.h:1269 [inline] __hci_req_sync+0x631/0x950 net/bluetooth/hci_request.c:184 hci_req_sync+0xa9/0xd0 net/bluetooth/hci_request.c:206 hci_dev_cmd+0x4c5/0xa50 net/bluetooth/hci_core.c:787 sock_do_ioctl+0x158/0x460 net/socket.c:1222 sock_ioctl+0x629/0x8e0 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f kfence-#236: 0xffff88823bdda000-0xffff88823bdda0ef, size=240, cache=skbuff_head_cache allocated by task 12388 on cpu 1 at 1546.489409s: skb_clone+0x20c/0x390 net/core/skbuff.c:2071 hci_send_cmd_sync net/bluetooth/hci_core.c:4123 [inline] hci_cmd_work+0x2a2/0x670 net/bluetooth/hci_core.c:4143 process_one_work kernel/workqueue.c:3248 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3329 worker_thread+0x86d/0xd50 kernel/workqueue.c:3409 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 freed by task 12388 on cpu 1 at 1546.489668s: kfree_skb_reason include/linux/skbuff.h:1260 [inline] kfree_skb include/linux/skbuff.h:1269 [inline] hci_req_sync_complete+0xe8/0x290 net/bluetooth/hci_request.c:109 hci_event_packet+0xc75/0x1540 net/bluetooth/hci_event.c:7479 hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4074 process_one_work kernel/workqueue.c:3248 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3329 worker_thread+0x86d/0xd50 kernel/workqueue.c:3409 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 CPU: 0 PID: 20339 Comm: syz-executor Not tainted 6.10.0-rc5-syzkaller-01207-ge19f67df9ccb #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] RIP: 0010:refcount_read include/linux/refcount.h:136 [inline] RIP: 0010:skb_unref include/linux/skbuff.h:1228 [inline] RIP: 0010:__sk_skb_reason_drop net/core/skbuff.c:1211 [inline] RIP: 0010:sk_skb_reason_drop+0x58/0x3d0 net/core/skbuff.c:1239 Code: ff df 49 8d 9d e4 00 00 00 48 89 df be 04 00 00 00 e8 2c 40 ab f8 48 89 d8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 f8 01 00 00 <8b> 2b bf 01 00 00 00 89 ee e8 ba 7c 45 f8 83 fd 01 0f 85 53 01 00 RSP: 0018:ffffc900033af9a0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88823bdda0e4 RCX: ffffffff8950ae84 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88823bdda0e4 RBP: ffffc900033afb68 R08: ffff88823bdda0e7 R09: 1ffff110477bb41c R10: dffffc0000000000 R11: ffffed10477bb41d R12: dffffc0000000000 R13: ffff88823bdda000 R14: 0000000000000002 R15: 0000000000000000 FS: 0000555587aa2500(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff88823bdda0e4 CR3: 000000002d1f2000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kfree_skb_reason include/linux/skbuff.h:1260 [inline] kfree_skb include/linux/skbuff.h:1269 [inline] __hci_req_sync+0x631/0x950 net/bluetooth/hci_request.c:184 hci_req_sync+0xa9/0xd0 net/bluetooth/hci_request.c:206 hci_dev_cmd+0x4c5/0xa50 net/bluetooth/hci_core.c:787 sock_do_ioctl+0x158/0x460 net/socket.c:1222 sock_ioctl+0x629/0x8e0 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff6543757db Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007fff9b7e8790 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007ff6543757db RDX: 00007fff9b7e8808 RSI: 00000000400448dd RDI: 0000000000000003 RBP: 0000555587aa24a8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000009 ================================================================== ---------------- Code disassembly (best guess), 1 bytes skipped: 0: df 49 8d fisttps -0x73(%rcx) 3: 9d popf 4: e4 00 in $0x0,%al 6: 00 00 add %al,(%rax) 8: 48 89 df mov %rbx,%rdi b: be 04 00 00 00 mov $0x4,%esi 10: e8 2c 40 ab f8 call 0xf8ab4041 15: 48 89 d8 mov %rbx,%rax 18: 48 c1 e8 03 shr $0x3,%rax 1c: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax 21: 84 c0 test %al,%al 23: 0f 85 f8 01 00 00 jne 0x221 * 29: 8b 2b mov (%rbx),%ebp <-- trapping instruction 2b: bf 01 00 00 00 mov $0x1,%edi 30: 89 ee mov %ebp,%esi 32: e8 ba 7c 45 f8 call 0xf8457cf1 37: 83 fd 01 cmp $0x1,%ebp 3a: 0f .byte 0xf 3b: 85 53 01 test %edx,0x1(%rbx)