usercopy: Kernel memory overwrite attempt detected to SLUB object 'task_struct' (offset 80, size 108)! ------------[ 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: 9627 Comm: syz.3.1306 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 : df991d90 ip : df991cd0 fp : df991db4 r10: 81a00568 r9 : 0000006c r8 : 843f1850 r7 : dde91dc0 r6 : 00000000 r5 : 0000006c r4 : 00000050 r3 : 849f2400 r2 : 00000000 r1 : 00000000 r0 : 00000066 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 852a9180 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 849f2400 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 843f1800 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 0xdf990000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2787 Register r12 information: 2-page vmalloc region starting at 0xdf990000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2787 Process syz.3.1306 (pid: 9627, stack limit = 0xdf990000) Stack: (0xdf991d90 to 0xdf992000) 1d80: 8205f678 82030fcc 820464dc 00000050 1da0: 0000006c 0000006c df991de4 df991db8 804d5d54 819be4f4 0000006c df991dc8 1dc0: 80214800 843f1850 0000006c 00000000 843f18bc dde91dc0 df991e1c df991de8 1de0: 80514b34 804d5c88 0000006c 20000084 df991e0c 843f1850 0000006c 20000084 1e00: 0000006c 81a005a0 0000006c 81a00568 df991e4c df991e20 80209db4 805148b8 1e20: 00000088 82f650c0 00000064 df991e2c df991e2c 80209d24 843f1800 20000084 1e40: df991ef4 df991e50 80253634 80209d30 00000000 20000000 20000000 81a0057c 1e60: 819e3204 00000000 df991eb4 df991e78 8020d0cc 8020c034 824bd180 00000000 1e80: 8027fa10 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1ea0: 00000000 849f2400 df991edc df991eb8 8027e354 802af5ec 00000000 00000000 1ec0: df991eec b6cd15cd 843f1800 20000080 00004202 00000002 00000000 20000080 1ee0: 849f2400 0000001a df991f6c df991ef8 8020a1e4 8025332c 843f1800 843f2084 1f00: df991f1c df991f10 819e36b0 8027c778 df991f6c df991f20 802813ec 819e368c 1f20: df991f54 00000000 8027e354 60000013 81990410 819a7694 df991f54 b6cd15cd 1f40: 00004205 843f1800 00004205 b6cd15cd 843f1800 00004205 00000002 00000000 1f60: df991fa4 df991f70 80252fdc 8020a140 80202cc0 b6cd15cd df991fac 00000000 1f80: 00000000 002862f4 0000001a 8020029c 849f2400 0000001a 00000000 df991fa8 1fa0: 80200060 80252db0 00000000 00000000 00004205 0000048b 00000002 20000080 1fc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76b720bc 1fe0: 76b71ec0 76b71eb0 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:dde91dc0 r7:843f18bc r6:00000000 r5:0000006c r4:843f1850 [<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 r9:0000006c r8:81a005a0 r7:0000006c r6:20000084 r5:0000006c r4:843f1850 [<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 r5:843f1800 r4:80209d24 [<80253320>] (ptrace_request) from [<8020a1e4>] (arch_ptrace+0xb0/0x424 arch/arm/kernel/ptrace.c:818) r10:0000001a r9:849f2400 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 r4:843f1800 [<80252da4>] (sys_ptrace) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdf991fa8 to 0xdf991ff0) 1fa0: 00000000 00000000 00004205 0000048b 00000002 20000080 1fc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76b720bc 1fe0: 76b71ec0 76b71eb0 00018af0 00133450 r10:0000001a r9:849f2400 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