Hello, I am writing to report a potential vulnerability identified in the Linux Kernel version 6.13.0-rc2. This issue was discovered using our custom vulnerability discovery tool. HEAD commit: fac04efc5c793dccbd07e2d59af9f90b7fc0dca4 (tag: v6.13-rc2) Detailed Call Stack: ------------[ cut here begin]------------ loop3: detected capacity change from 0 to 128 rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 3-.... } 5 jiffies s: 1465 root: 0x8/. rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 1 to CPUs 3: NMI backtrace for cpu 3 CPU: 3 UID: 0 PID: 15107 Comm: syz-executor.5 Tainted: G U 6.13.0-rc2-00159-gf932fb9b4074 #1 Tainted: [U]=USER Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:149 [inline] RIP: 0010:wrmsrl arch/x86/include/asm/msr.h:264 [inline] RIP: 0010:lapic_next_deadline+0x25/0x50 arch/x86/kernel/apic/apic.c:428 Code: 90 90 90 90 90 f3 0f 1e fa 66 0f 1f 44 00 00 0f 31 48 c1 e2 20 b9 e0 06 00 00 48 09 c2 48 8d 04 fa 48 89 c2 48 c1 ea 20 0f 30 <66> 90 31 c0 e9 52 78 f8 02 48 89 c6 31 d2 bf e0 06 00 00 e8 63 68 RSP: 0018:ffff88811b389780 EFLAGS: 00000012 RAX: 00000068262333d9 RBX: ffff88811b3a8280 RCX: 00000000000006e0 RDX: 0000000000000068 RSI: ffff88811b3a8280 RDI: 00000000000001c7 RBP: 00000000000001c7 R08: 0000000000000001 R09: ffffed10236712d2 R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000003 R14: ffff88811b3ac878 R15: ffff88811b3ac8b8 FS: 00007fbaec3f2640(0000) GS:ffff88811b380000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055804c171de8 CR3: 000000000489c000 CR4: 0000000000350ef0 Call Trace: <NMI> </NMI> <IRQ> clockevents_program_event+0x208/0x310 kernel/time/clockevents.c:334 tick_program_event+0x72/0x100 kernel/time/tick-oneshot.c:44 hrtimer_interrupt+0x335/0x770 kernel/time/hrtimer.c:1878 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x88/0x260 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x32/0x80 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:unwind_next_frame+0x451/0x2440 arch/x86/kernel/unwind_orc.c:505 Code: 48 85 c0 75 0c e9 1a 02 00 00 48 c7 c1 a0 ba aa a3 48 b8 00 00 00 00 00 fc ff df 4c 8d 79 05 4c 89 fa 48 c1 ea 03 0f b6 04 02 <4c> 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 a1 16 00 00 0f b6 41 05 RSP: 0018:ffff88811b389958 EFLAGS: 00000216 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffffa4652644 RDX: 1ffffffff48ca4c9 RSI: 0000000000000000 RDI: ffffffffa432bcd8 RBP: ffff88811b389a20 R08: ffffffffa465267a R09: ffff88811b389a08 R10: ffff88811b3899c8 R11: 00000000000087a0 R12: ffff88811b389a28 R13: ffff88811b3899c8 R14: ffff88811b389a09 R15: ffffffffa4652649 arch_stack_walk+0x95/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8f/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x37/0x50 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2338 [inline] slab_free mm/slub.c:4598 [inline] kfree+0xea/0x370 mm/slub.c:4746 slab_free_after_rcu_debug+0x6f/0x2a0 mm/slub.c:4635 rcu_do_batch kernel/rcu/tree.c:2567 [inline] rcu_core+0x613/0x1a80 kernel/rcu/tree.c:2823 handle_softirqs+0x1b8/0x5c0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu kernel/softirq.c:662 [inline] irq_exit_rcu+0xaf/0xe0 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x6c/0x80 arch/x86/kernel/apic/apic.c:1049 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x15c/0x1b0 mm/kasan/generic.c:189 Code: c2 48 85 c0 75 ad 48 89 da 4c 89 d8 4c 29 da e9 46 ff ff ff 48 85 d2 74 18 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 0a 80 38 00 <74> f2 e9 75 ff ff ff 5b b8 01 00 00 00 5d 41 5c e9 2f 13 91 02 b8 RSP: 0018:ffff8881078bf878 EFLAGS: 00000202 RAX: fffffbfff4ac2510 RBX: fffffbfff4ac2511 RCX: ffffffffa2a89bb1 RDX: fffffbfff4ac2511 RSI: 0000000000000004 RDI: ffffffffa5612880 RBP: fffffbfff4ac2510 R08: 0000000000000001 R09: fffffbfff4ac2510 R10: ffffffffa5612883 R11: 0000000000000176 R12: 0000000000000001 R13: ffff8881078bfa80 R14: ffff888009e2b800 R15: ffff8881078bfad0 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1300 [inline] queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] do_raw_spin_lock include/linux/spinlock.h:187 [inline] __raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline] _raw_spin_lock+0x71/0xe0 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] locks_start+0x8f/0xf0 fs/locks.c:2941 seq_read_iter+0x278/0x10c0 fs/seq_file.c:225 proc_reg_read_iter+0x1dd/0x2b0 fs/proc/inode.c:299 copy_splice_read+0x55f/0xa60 fs/splice.c:365 do_splice_read fs/splice.c:985 [inline] do_splice_read+0x1ab/0x250 fs/splice.c:959 splice_direct_to_actor+0x26a/0x9f0 fs/splice.c:1089 do_splice_direct_actor fs/splice.c:1207 [inline] do_splice_direct+0x15d/0x220 fs/splice.c:1233 do_sendfile+0x9ea/0xde0 fs/read_write.c:1363 __do_sys_sendfile64 fs/read_write.c:1424 [inline] __se_sys_sendfile64 fs/read_write.c:1410 [inline] __x64_sys_sendfile64+0x19f/0x1e0 fs/read_write.c:1410 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xa6/0x1a0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbaed37842d Code: c3 e8 97 2b 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fbaec3f2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fbaed56c1f0 RCX: 00007fbaed37842d RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005 RBP: 00007fbaed437922 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000400000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007fbaed56c1f0 R15: 00007fbaec3d2000 </TASK> rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 3-.... } 27 jiffies s: 1465 root: 0x8/. rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 1 to CPUs 3: NMI backtrace for cpu 3 CPU: 3 UID: 0 PID: 15107 Comm: syz-executor.5 Tainted: G U 6.13.0-rc2-00159-gf932fb9b4074 #1 Tainted: [U]=USER Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:__read_once_word_nocheck+0x0/0x10 include/asm-generic/rwonce.h:67 Code: a6 fd ff ff e8 c1 e8 64 00 e9 5f fd ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <48> 8b 07 e9 d8 f5 f5 02 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 RSP: 0018:ffff88811b389908 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffff8881078c0000 RDX: ffff8881078bf801 RSI: ffff8881078bf878 RDI: ffff8881078bf878 RBP: ffff8881078bf878 R08: 0000000000000001 R09: ffff88811b3899c0 R10: ffff88811b389980 R11: 00000000000084b8 R12: ffff88811b3899e0 R13: ffff88811b389980 R14: ffff8881078bf888 R15: ffff8881078bf880 FS: 00007fbaec3f2640(0000) GS:ffff88811b380000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055804c171de8 CR3: 000000000489c000 CR4: 0000000000350ef0 Call Trace: <NMI> </NMI> <IRQ> deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline] unwind_next_frame+0xc42/0x2440 arch/x86/kernel/unwind_orc.c:648 arch_stack_walk+0x95/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8f/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0x8e/0xa0 mm/kasan/generic.c:544 __call_rcu_common.constprop.0+0x6b/0xa90 kernel/rcu/tree.c:3086 kmemleak_free_recursive include/linux/kmemleak.h:49 [inline] slab_free_hook mm/slub.c:2263 [inline] slab_free mm/slub.c:4598 [inline] kfree+0x1ef/0x370 mm/slub.c:4746 slab_free_after_rcu_debug+0x6f/0x2a0 mm/slub.c:4635 rcu_do_batch kernel/rcu/tree.c:2567 [inline] rcu_core+0x613/0x1a80 kernel/rcu/tree.c:2823 handle_softirqs+0x1b8/0x5c0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu kernel/softirq.c:662 [inline] irq_exit_rcu+0xaf/0xe0 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x6c/0x80 arch/x86/kernel/apic/apic.c:1049 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__sanitizer_cov_trace_pc+0x56/0x80 kernel/kcov.c:222 Code: 00 f0 00 75 3c 8b 82 a4 0a 00 00 85 c0 74 32 8b 82 80 0a 00 00 83 f8 02 75 27 48 8b b2 88 0a 00 00 8b 92 84 0a 00 00 48 8b 06 <48> 83 c0 01 48 39 d0 73 0e 48 89 06 48 81 e9 00 00 a0 1e 48 89 0c RSP: 0018:ffff8881078bf588 EFLAGS: 00000246 RAX: 00000000000001ae RBX: ffff88800d37c000 RCX: ffffffffa2a3ea2d RDX: 0000000000040000 RSI: ffffc90003db9000 RDI: ffffffffa2facda1 RBP: ffff88800d37c001 R08: 0000000000000000 R09: ffff8881064bb230 R10: 0000000000000003 R11: 0000000000000176 R12: ffff88800d37d000 R13: 00000000fffffffc R14: ffff8881078bf628 R15: dffffc0000000000 number+0x66d/0x970 lib/vsprintf.c:565 vsnprintf+0x8d3/0x16e0 lib/vsprintf.c:2914 seq_vprintf fs/seq_file.c:391 [inline] seq_printf+0x1a5/0x260 fs/seq_file.c:406 lock_get_status+0x187/0x760 fs/locks.c:2776 locks_show+0x208/0x3c0 fs/locks.c:2873 seq_read_iter+0x470/0x10c0 fs/seq_file.c:230 proc_reg_read_iter+0x1dd/0x2b0 fs/proc/inode.c:299 copy_splice_read+0x55f/0xa60 fs/splice.c:365 do_splice_read fs/splice.c:985 [inline] do_splice_read+0x1ab/0x250 fs/splice.c:959 splice_direct_to_actor+0x26a/0x9f0 fs/splice.c:1089 do_splice_direct_actor fs/splice.c:1207 [inline] do_splice_direct+0x15d/0x220 fs/splice.c:1233 do_sendfile+0x9ea/0xde0 fs/read_write.c:1363 __do_sys_sendfile64 fs/read_write.c:1424 [inline] __se_sys_sendfile64 fs/read_write.c:1410 [inline] __x64_sys_sendfile64+0x19f/0x1e0 fs/read_write.c:1410 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xa6/0x1a0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbaed37842d Code: c3 e8 97 2b 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fbaec3f2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fbaed56c1f0 RCX: 00007fbaed37842d RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005 RBP: 00007fbaed437922 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000400000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007fbaed56c1f0 R15: 00007fbaec3d2000 </TASK> loop7: detected capacity change from 0 to 1024 EXT4-fs: Journaled quota options ignored when QUOTA feature is enabled loop2: detected capacity change from 0 to 1024 EXT4-fs error (device loop7): ext4_orphan_get:1415: comm syz-executor.7: bad orphan inode 83886080 EXT4-fs (loop7): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback. EXT4-fs (loop2): orphan cleanup on readonly fs EXT4-fs error (device loop2): ext4_orphan_get:1415: comm syz-executor.2: bad orphan inode 83886080 EXT4-fs (loop2): mounting with "discard" option, but the device does not support discard EXT4-fs (loop7): unmounting filesystem 00000000-0000-0000-0000-000000000000. EXT4-fs (loop2): mounted filesystem 00000000-0000-0000-0000-000000000000 ro without journal. Quota mode: writeback. EXT4-fs (loop2): unmounting filesystem 00000000-0000-0000-0000-000000000000. ------------[ cut here end]------------ Thank you for your time and attention. Best regards Wall