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: 10912 Comm: syz.9.1085 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:4525 pc : [<819be580>] lr : [<802be434>] psr: 60000013 sp : dfb8dd90 ip : dfb8dcd0 fp : dfb8ddb4 r10: 81a00568 r9 : 00000078 r8 : 84800c50 r7 : dde9b000 r6 : 00000000 r5 : 00000074 r4 : 00000050 r3 : 84804800 r2 : 00000000 r1 : 00000000 r0 : 00000066 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 84d005c0 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 84804800 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 84800c00 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 0xdfb8c000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2787 Register r12 information: 2-page vmalloc region starting at 0xdfb8c000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2787 Process syz.9.1085 (pid: 10912, stack limit = 0xdfb8c000) Stack: (0xdfb8dd90 to 0xdfb8e000) dd80: 8205f678 82030fcc 820464dc 00000050 dda0: 00000074 00000078 dfb8dde4 dfb8ddb8 804d5d54 819be4f4 00000074 dfb8ddc8 ddc0: 80214800 84800c50 00000074 00000000 84800cc4 dde9b000 dfb8de1c dfb8dde8 dde0: 80514b34 804d5c88 00000074 20000084 dfb8de0c 84800c50 00000074 20000084 de00: 00000074 81a005a0 00000078 81a00568 dfb8de4c dfb8de20 80209db4 805148b8 de20: 00000000 00000001 802856d4 00000008 00000000 80209d24 84800c00 20000084 de40: dfb8def4 dfb8de50 80253634 80209d30 00000000 20000000 20000000 81a0057c de60: 8027e33c 00000000 84804800 ffffffff dfb8dedc 80200be4 84804800 0000001a de80: dfb8dea4 00000000 00000000 00000000 00000000 00000000 00000000 00000000 dea0: 00000000 819db038 84800c00 00004205 00000002 20000080 20000080 00004202 dec0: 00000002 4dab1989 20000080 20000080 00004202 00000002 00000000 20000080 dee0: 84804800 0000001a dfb8df6c dfb8def8 8020a1e4 8025332c 84800c00 84801484 df00: dfb8df1c dfb8df10 819e36b0 8027c778 dfb8df6c dfb8df20 802813ec 819e368c df20: dfb8df54 00000000 8027e354 60000013 81990410 819a7694 dfb8df54 4dab1989 df40: 00004205 84800c00 00004205 4dab1989 84800c00 00004205 00000002 00000000 df60: dfb8dfa4 dfb8df70 80252fdc 8020a140 80202cc0 4dab1989 dfb8dfac 00000000 df80: 00000000 002862f4 0000001a 8020029c 84804800 0000001a 00000000 dfb8dfa8 dfa0: 80200060 80252db0 00000000 00000000 00004205 00000103 00000002 20000080 dfc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76b830bc dfe0: 76b82ec0 76b82eb0 00018af0 00133450 60000010 00004205 00000000 00000000 Call trace: [<819be4e8>] (usercopy_abort) from [<804d5d54>] (__check_heap_object+0xd8/0xf4 mm/slub.c:5651) [<804d5c7c>] (__check_heap_object) from [<80514b34>] (check_heap_object mm/usercopy.c:196 [inline]) [<804d5c7c>] (__check_heap_object) from [<80514b34>] (__check_object_size mm/usercopy.c:251 [inline]) [<804d5c7c>] (__check_heap_object) from [<80514b34>] (__check_object_size+0x288/0x304 mm/usercopy.c:213) r8:dde9b000 r7:84800cc4 r6:00000000 r5:00000074 r4:84800c50 [<805148ac>] (__check_object_size) from [<80209db4>] (check_object_size include/linux/thread_info.h:228 [inline]) [<805148ac>] (__check_object_size) from [<80209db4>] (__copy_from_user include/linux/uaccess.h:110 [inline]) [<805148ac>] (__check_object_size) from [<80209db4>] (user_regset_copyin include/linux/regset.h:268 [inline]) [<805148ac>] (__check_object_size) from [<80209db4>] (fpa_set+0x90/0x118 arch/arm/kernel/ptrace.c:587) r10:81a00568 r9:00000078 r8:81a005a0 r7:00000074 r6:20000084 r5:00000074 r4:84800c50 [<80209d24>] (fpa_set) from [<80253634>] (copy_regset_from_user include/linux/regset.h:337 [inline]) [<80209d24>] (fpa_set) from [<80253634>] (ptrace_regset kernel/ptrace.c:906 [inline]) [<80209d24>] (fpa_set) from [<80253634>] (ptrace_request+0x314/0xa78 kernel/ptrace.c:1218) r6:20000084 r5:84800c00 r4:80209d24 [<80253320>] (ptrace_request) from [<8020a1e4>] (arch_ptrace+0xb0/0x424 arch/arm/kernel/ptrace.c:818) r10:0000001a r9:84804800 r8:20000080 r7:00000000 r6:00000002 r5:00004202 r4:20000080 [<8020a134>] (arch_ptrace) from [<80252fdc>] (__do_sys_ptrace kernel/ptrace.c:1285 [inline]) [<8020a134>] (arch_ptrace) from [<80252fdc>] (sys_ptrace+0x238/0x4dc kernel/ptrace.c:1258) r7:00000000 r6:00000002 r5:00004205 r4:84800c00 [<80252da4>] (sys_ptrace) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfb8dfa8 to 0xdfb8dff0) dfa0: 00000000 00000000 00004205 00000103 00000002 20000080 dfc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76b830bc dfe0: 76b82ec0 76b82eb0 00018af0 00133450 r10:0000001a r9:84804800 r8:8020029c r7:0000001a r6:002862f4 r5:00000000 r4:00000000 Code: e30f067c e3480205 e58dc000 ebfff265 (e7f001f2) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: e30f067c movw r0, #63100 @ 0xf67c 4: e3480205 movt r0, #33285 @ 0x8205 8: e58dc000 str ip, [sp] c: ebfff265 bl 0xffffc9a8 * 10: e7f001f2 udf #18 <-- trapping instruction