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: 1 UID: 0 PID: 16232 Comm: syz.1.2597 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 : [<819a6788>] lr : [<802bcae4>] psr: 60000013 sp : dfc6dd90 ip : dfc6dcd0 fp : dfc6ddb4 r10: 81a00568 r9 : 00000078 r8 : 8458c850 r7 : dde95720 r6 : 00000000 r5 : 00000074 r4 : 00000050 r3 : 84588c00 r2 : 00000000 r1 : 00000000 r0 : 00000066 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 84fa87c0 DAC: 00000000 Register r0 information: non-paged memory Register r1 information: NULL pointer Register r2 information: NULL pointer Register r3 information: slab task_struct start 84588c00 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 8458c800 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 0xdfc6c000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2786 Register r12 information: 2-page vmalloc region starting at 0xdfc6c000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2786 Process syz.1.2597 (pid: 16232, stack limit = 0xdfc6c000) Stack: (0xdfc6dd90 to 0xdfc6e000) dd80: 8205cb40 8202e418 82043a48 00000050 dda0: 00000074 00000078 dfc6dde4 dfc6ddb8 804d0068 819a66fc 00000074 dfc6ddc8 ddc0: 802147e0 8458c850 00000074 00000000 8458c8c4 dde95720 dfc6de1c dfc6dde8 dde0: 8050ef2c 804cff9c 00000074 20000084 dfc6de0c 8458c850 00000074 20000084 de00: 00000074 81a005a0 00000078 81a00568 dfc6de4c dfc6de20 80209d94 8050ecb0 de20: dfc6def4 82e5c280 00000064 dfc6de2c dfc6de2c 80209d04 8458c800 20000084 de40: dfc6def4 dfc6de50 80252ed0 80209d10 00000000 20000000 20000000 81a0057c de60: 819cb6bc 00000000 dfc6deb4 dfc6de78 8020d0ac 8020c014 dfc6de94 00000000 de80: 8027eba4 00000000 00000000 00000000 00000000 00000000 00000000 00000000 dea0: 00000000 84588c00 dfc6dedc dfc6deb8 8027d3d4 802ae61c 00000000 00000000 dec0: dfc6deec 068409eb 8458c800 20000080 00004202 00000002 00000000 20000080 dee0: 84588c00 0000001a dfc6df6c dfc6def8 8020a1c4 80252bc8 8458c800 8458d084 df00: dfc6df1c dfc6df10 819cbb68 8027b950 dfc6df6c dfc6df20 80280564 819cbb44 df20: dfc6df54 00000000 8027d3d4 60000013 81978650 8198f8d4 dfc6df54 068409eb df40: 8458c800 00004205 8458c800 068409eb 00004205 8458c800 00000002 00000000 df60: dfc6dfa4 dfc6df70 80252874 8020a120 80202cc0 068409eb dfc6dfac 00000000 df80: 00000000 002862f4 0000001a 8020029c 84588c00 0000001a 00000000 dfc6dfa8 dfa0: 80200060 80252648 00000000 00000000 00004205 000000fd 00000002 20000080 dfc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76ba20bc dfe0: 76ba1ec0 76ba1eb0 00018af0 00133450 60000010 00004205 00000000 00000000 Call trace: [<819a66f0>] (usercopy_abort) from [<804d0068>] (__check_heap_object+0xd8/0xf4 mm/slub.c:5651) [<804cff90>] (__check_heap_object) from [<8050ef2c>] (check_heap_object mm/usercopy.c:196 [inline]) [<804cff90>] (__check_heap_object) from [<8050ef2c>] (__check_object_size mm/usercopy.c:251 [inline]) [<804cff90>] (__check_heap_object) from [<8050ef2c>] (__check_object_size+0x288/0x304 mm/usercopy.c:213) r8:dde95720 r7:8458c8c4 r6:00000000 r5:00000074 r4:8458c850 [<8050eca4>] (__check_object_size) from [<80209d94>] (check_object_size include/linux/thread_info.h:215 [inline]) [<8050eca4>] (__check_object_size) from [<80209d94>] (__copy_from_user include/linux/uaccess.h:110 [inline]) [<8050eca4>] (__check_object_size) from [<80209d94>] (user_regset_copyin include/linux/regset.h:268 [inline]) [<8050eca4>] (__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 r4:8458c850 [<80209d04>] (fpa_set) from [<80252ed0>] (copy_regset_from_user include/linux/regset.h:337 [inline]) [<80209d04>] (fpa_set) from [<80252ed0>] (ptrace_regset kernel/ptrace.c:906 [inline]) [<80209d04>] (fpa_set) from [<80252ed0>] (ptrace_request+0x314/0xa78 kernel/ptrace.c:1218) r6:20000084 r5:8458c800 r4:80209d04 [<80252bbc>] (ptrace_request) from [<8020a1c4>] (arch_ptrace+0xb0/0x424 arch/arm/kernel/ptrace.c:818) r10:0000001a r9:84588c00 r8:20000080 r7:00000000 r6:00000002 r5:00004202 r4:20000080 [<8020a114>] (arch_ptrace) from [<80252874>] (__do_sys_ptrace kernel/ptrace.c:1285 [inline]) [<8020a114>] (arch_ptrace) from [<80252874>] (sys_ptrace+0x238/0x4e0 kernel/ptrace.c:1258) r7:00000000 r6:00000002 r5:8458c800 r4:00004205 [<8025263c>] (sys_ptrace) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfc6dfa8 to 0xdfc6dff0) dfa0: 00000000 00000000 00004205 000000fd 00000002 20000080 dfc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76ba20bc dfe0: 76ba1ec0 76ba1eb0 00018af0 00133450 r10:0000001a r9:84588c00 r8:8020029c r7:0000001a r6:002862f4 r5:00000000 r4:00000000 Code: e30c0b44 e3480205 e58dc000 ebfff273 (e7f001f2) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: e30c0b44 movw r0, #52036 @ 0xcb44 4: e3480205 movt r0, #33285 @ 0x8205 8: e58dc000 str ip, [sp] c: ebfff273 bl 0xffffc9e0 * 10: e7f001f2 udf #18 <-- trapping instruction