usercopy: Kernel memory overwrite attempt detected to SLUB object 'task_struct' (offset 80, size 116)! ------------[ cut here ]------------ kernel BUG at mm/usercopy.c:102! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 11768 Comm: syz.2.1855 Not tainted 6.12.0-syzkaller #0 Hardware name: ARM-Versatile Express PC is at usercopy_abort+0x98/0x9c mm/usercopy.c:102 LR is at __wake_up_klogd.part.0+0x7c/0xac kernel/printk/printk.c:4495 pc : [<819ad1a8>] lr : [<802bd0cc>] psr: 60000013 sp : e0055d90 ip : e0055cd0 fp : e0055db4 r10: 81a00568 r9 : 00000078 r8 : 83d56050 r7 : dde82f40 r6 : 00000000 r5 : 00000074 r4 : 00000050 r3 : 83d51800 r2 : 00000000 r1 : 00000000 r0 : 00000066 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 8574c300 DAC: fffffffd Register r0 information: non-paged memory Register r1 information: NULL pointer Register r2 information: NULL pointer Register r3 information: slab task_struct start 83d51800 pointer offset 0 size 3072 Register r4 information: non-paged memory Register r5 information: non-paged memory Register r6 information: NULL pointer Register r7 information: non-slab/vmalloc memory Register r8 information: slab task_struct start 83d56000 pointer offset 80 size 3072 Register r9 information: non-paged memory Register r10 information: non-slab/vmalloc memory Register r11 information: 2-page vmalloc region starting at 0xe0054000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2786 Register r12 information: 2-page vmalloc region starting at 0xe0054000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2786 Process syz.2.1855 (pid: 11768, stack limit = 0xe0054000) Stack: (0xe0055d90 to 0xe0056000) 5d80: 8205dcc0 8202f54c 82044bc8 00000050 5da0: 00000074 00000078 e0055de4 e0055db8 804d0a68 819ad11c 00000074 e0055dc8 5dc0: 802147e0 83d56050 00000074 00000000 83d560c4 dde82f40 e0055e1c e0055de8 5de0: 8050f834 804d099c 00000074 20000084 e0055e0c 83d56050 00000074 20000084 5e00: 00000074 81a005a0 00000078 81a00568 e0055e4c e0055e20 80209d94 8050f5b8 5e20: e0055e64 82e55c80 00000064 e0055e2c e0055e2c 80209d04 83d56000 20000084 5e40: e0055ef4 e0055e50 8025337c 80209d10 00000000 20000000 20000000 81a0057c 5e60: 819d1d04 00000000 e0055eb4 e0055e78 8020d0ac 8020c014 824bc3c0 00000000 5e80: 8027f0d4 00000000 00000000 00000000 00000000 00000000 00000000 00000000 5ea0: 00000000 83d51800 e0055edc e0055eb8 e0055f1c e0055ec0 80200bcc 8197608c 5ec0: 83d56884 4ec9e617 00000001 20000080 00004202 00000002 00000000 20000080 5ee0: 83d51800 0000001a e0055f6c e0055ef8 8020a1c4 80253074 80280a94 819d21a8 5f00: e0055f1c e0055f10 819d21b0 8027be80 e0055f6c e0055f20 80280a94 819d218c 5f20: e0055f54 00000000 8027d904 60000013 8197f070 819962f4 e0055f54 4ec9e617 5f40: 83d56000 00004205 83d56000 4ec9e617 00004205 83d56000 00000002 00000000 5f60: e0055fa4 e0055f70 80252d20 8020a120 80202cc0 4ec9e617 e0055fac 00000000 5f80: 00000000 002862f4 0000001a 8020029c 83d51800 0000001a 00000000 e0055fa8 5fa0: 80200060 80252af4 00000000 00000000 00004205 00000071 00000002 20000080 5fc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76bac0bc 5fe0: 76babec0 76babeb0 00018af0 00133450 60000010 00004205 00000000 00000000 Call trace: [<819ad110>] (usercopy_abort) from [<804d0a68>] (__check_heap_object+0xd8/0xf4 mm/slub.c:5651) [<804d0990>] (__check_heap_object) from [<8050f834>] (check_heap_object mm/usercopy.c:196 [inline]) [<804d0990>] (__check_heap_object) from [<8050f834>] (__check_object_size mm/usercopy.c:251 [inline]) [<804d0990>] (__check_heap_object) from [<8050f834>] (__check_object_size+0x288/0x304 mm/usercopy.c:213) r8:dde82f40 r7:83d560c4 r6:00000000 r5:00000074 r4:83d56050 [<8050f5ac>] (__check_object_size) from [<80209d94>] (check_object_size include/linux/thread_info.h:215 [inline]) [<8050f5ac>] (__check_object_size) from [<80209d94>] (__copy_from_user include/linux/uaccess.h:110 [inline]) [<8050f5ac>] (__check_object_size) from [<80209d94>] (user_regset_copyin include/linux/regset.h:268 [inline]) [<8050f5ac>] (__check_object_size) from [<80209d94>] (fpa_set+0x90/0x118 arch/arm/kernel/ptrace.c:587) r10:81a00568 r9:00000078 r8:81a005a0 r7:00000074 r6:20000084 r5:00000074 r4:83d56050 [<80209d04>] (fpa_set) from [<8025337c>] (copy_regset_from_user include/linux/regset.h:337 [inline]) [<80209d04>] (fpa_set) from [<8025337c>] (ptrace_regset kernel/ptrace.c:906 [inline]) [<80209d04>] (fpa_set) from [<8025337c>] (ptrace_request+0x314/0xa78 kernel/ptrace.c:1218) r6:20000084 r5:83d56000 r4:80209d04 [<80253068>] (ptrace_request) from [<8020a1c4>] (arch_ptrace+0xb0/0x424 arch/arm/kernel/ptrace.c:818) r10:0000001a r9:83d51800 r8:20000080 r7:00000000 r6:00000002 r5:00004202 r4:20000080 [<8020a114>] (arch_ptrace) from [<80252d20>] (__do_sys_ptrace kernel/ptrace.c:1285 [inline]) [<8020a114>] (arch_ptrace) from [<80252d20>] (sys_ptrace+0x238/0x4e0 kernel/ptrace.c:1258) r7:00000000 r6:00000002 r5:83d56000 r4:00004205 [<80252ae8>] (sys_ptrace) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xe0055fa8 to 0xe0055ff0) 5fa0: 00000000 00000000 00004205 00000071 00000002 20000080 5fc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76bac0bc 5fe0: 76babec0 76babeb0 00018af0 00133450 r10:0000001a r9:83d51800 r8:8020029c r7:0000001a r6:002862f4 r5:00000000 r4:00000000 Code: e30d0cc4 e3480205 e58dc000 ebfff273 (e7f001f2) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: e30d0cc4 movw r0, #56516 @ 0xdcc4 4: e3480205 movt r0, #33285 @ 0x8205 8: e58dc000 str ip, [sp] c: ebfff273 bl 0xffffc9e0 * 10: e7f001f2 udf #18 <-- trapping instruction