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: 7295 Comm: syz.2.864 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 : [<819a3a08>] lr : [<802bcaa4>] psr: 60000013 sp : dfdddd90 ip : dfdddcd0 fp : dfddddb4 r10: 81a00568 r9 : 00000078 r8 : 83f9ec50 r7 : dde88160 r6 : 00000000 r5 : 00000074 r4 : 00000050 r3 : 83f9d400 r2 : 00000000 r1 : 00000000 r0 : 00000066 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 84d5bac0 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 83f9d400 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 83f9ec00 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 0xdfddc000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2786 Register r12 information: 2-page vmalloc region starting at 0xdfddc000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2786 Process syz.2.864 (pid: 7295, stack limit = 0xdfddc000) Stack: (0xdfdddd90 to 0xdfdde000) dd80: 8205bffc 8202d9f4 82043040 00000050 dda0: 00000074 00000078 dfdddde4 dfddddb8 804cf8f8 819a397c 00000074 dfddddc8 ddc0: 802147e0 83f9ec50 00000074 00000000 83f9ecc4 dde88160 dfddde1c dfdddde8 dde0: 8050e7bc 804cf82c 00000074 20000084 dfddde0c 83f9ec50 00000074 20000084 de00: 00000074 81a005a0 00000078 81a00568 dfddde4c dfddde20 80209d94 8050e540 de20: 00000000 00000000 00000000 00000000 00000000 80209d04 83f9ec00 20000084 de40: dfdddef4 dfddde50 80252ed0 80209d10 00000000 20000000 20000000 81a0057c de60: 819c893c 00000000 dfdddeb4 dfddde78 8020d0ac 8020c014 00000000 00000000 de80: 8027eba4 00000000 00000000 00000000 00000000 00000000 00000000 00000000 dea0: 00000000 83f9d400 dfdddedc dfdddeb8 8027d3d4 802ae5dc 00000000 00000000 dec0: dfdddeec b14fac25 83f9ec00 20000080 00004202 00000002 00000000 20000080 dee0: 83f9d400 0000001a dfdddf6c dfdddef8 8020a1c4 80252bc8 83f9ec00 83f9f484 df00: dfdddf1c dfdddf10 819c8de8 8027b950 dfdddf6c dfdddf20 80280564 819c8dc4 df20: dfdddf54 00000000 8027d3d4 60000013 819758d0 8198cb54 dfdddf54 b14fac25 df40: 83f9ec00 00004205 83f9ec00 b14fac25 00004205 83f9ec00 00000002 00000000 df60: dfdddfa4 dfdddf70 80252874 8020a120 80202cc0 b14fac25 dfdddfac 00000000 df80: 00000000 002862f4 0000001a 8020029c 83f9d400 0000001a 00000000 dfdddfa8 dfa0: 80200060 80252648 00000000 00000000 00004205 000001cc 00000002 20000080 dfc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76bc30bc dfe0: 76bc2ec0 76bc2eb0 00018af0 00133450 60000010 00004205 00000000 00000000 Call trace: [<819a3970>] (usercopy_abort) from [<804cf8f8>] (__check_heap_object+0xd8/0xf4 mm/slub.c:5651) [<804cf820>] (__check_heap_object) from [<8050e7bc>] (check_heap_object mm/usercopy.c:196 [inline]) [<804cf820>] (__check_heap_object) from [<8050e7bc>] (__check_object_size mm/usercopy.c:251 [inline]) [<804cf820>] (__check_heap_object) from [<8050e7bc>] (__check_object_size+0x288/0x304 mm/usercopy.c:213) r8:dde88160 r7:83f9ecc4 r6:00000000 r5:00000074 r4:83f9ec50 [<8050e534>] (__check_object_size) from [<80209d94>] (check_object_size include/linux/thread_info.h:215 [inline]) [<8050e534>] (__check_object_size) from [<80209d94>] (__copy_from_user include/linux/uaccess.h:110 [inline]) [<8050e534>] (__check_object_size) from [<80209d94>] (user_regset_copyin include/linux/regset.h:268 [inline]) [<8050e534>] (__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 r4:83f9ec50 [<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 r5:83f9ec00 r4:80209d04 [<80252bbc>] (ptrace_request) from [<8020a1c4>] (arch_ptrace+0xb0/0x424 arch/arm/kernel/ptrace.c:818) r10:0000001a r9:83f9d400 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 r5:83f9ec00 r4:00004205 [<8025263c>] (sys_ptrace) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfdddfa8 to 0xdfdddff0) dfa0: 00000000 00000000 00004205 000001cc 00000002 20000080 dfc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76bc30bc dfe0: 76bc2ec0 76bc2eb0 00018af0 00133450 r10:0000001a r9:83f9d400 r8:8020029c r7:0000001a r6:002862f4 r5:00000000 r4:00000000 Code: e30c0000 e3480205 e58dc000 ebfff273 (e7f001f2) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: e30c0000 movw r0, #49152 @ 0xc000 4: e3480205 movt r0, #33285 @ 0x8205 8: e58dc000 str ip, [sp] c: ebfff273 bl 0xffffc9e0 * 10: e7f001f2 udf #18 <-- trapping instruction