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: 4254 Comm: syz.0.121 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 : dfdb5e38 ip : dfdb5d78 fp : dfdb5e5c r10: 0000001a r9 : 843dbc00 r8 : 843dec50 r7 : dde91a60 r6 : 00000000 r5 : 00000074 r4 : 00000050 r3 : 843dbc00 r2 : 00000000 r1 : 00000000 r0 : 00000066 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 84c62180 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 843dbc00 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 843dec00 pointer offset 80 size 3072 Register r9 information: slab task_struct start 843dbc00 pointer offset 0 size 3072 Register r10 information: non-paged memory Register r11 information: 2-page vmalloc region starting at 0xdfdb4000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2787 Register r12 information: 2-page vmalloc region starting at 0xdfdb4000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2787 Process syz.0.121 (pid: 4254, stack limit = 0xdfdb4000) Stack: (0xdfdb5e38 to 0xdfdb6000) 5e20: 8205f678 82030fcc 5e40: 820464dc 00000050 00000074 843dbc00 dfdb5e8c dfdb5e60 804d5d54 819be4f4 5e60: 00000074 dfdb5e70 80214800 843dec50 00000074 00000000 843decc4 dde91a60 5e80: dfdb5ec4 dfdb5e90 80514b34 804d5c88 00000074 0000000a dfdb5eb4 843dec50 5ea0: 00000074 0000000a 00000000 20000040 843dbc00 0000001a dfdb5ef4 dfdb5ec8 5ec0: 80209db4 805148b8 843dec00 ddde4180 dfdb5ef4 dfdb5ee0 819e37e4 20000040 5ee0: 0000000c 0000000a dfdb5f6c dfdb5ef8 8020a468 80209d30 00000000 20000040 5f00: dfdb5f1c dfdb5f10 819e36b0 8027c778 dfdb5f6c dfdb5f20 802813ec 819e368c 5f20: dfdb5f54 00000000 8027e354 60000013 81990410 819a7694 dfdb5f54 16d98d89 5f40: 0000000f 843dec00 0000000f 16d98d89 843dec00 0000000f 0000000a 00000000 5f60: dfdb5fa4 dfdb5f70 80252fdc 8020a140 80202cc0 16d98d89 dfdb5fac 00000000 5f80: 00000000 002862f4 0000001a 8020029c 843dbc00 0000001a 00000000 dfdb5fa8 5fa0: 80200060 80252db0 00000000 00000000 0000000f 000000b7 0000000a 20000040 5fc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76b150bc 5fe0: 76b14ec0 76b14eb0 00018af0 00133450 60000010 0000000f 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:dde91a60 r7:843decc4 r6:00000000 r5:00000074 r4:843dec50 [<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) r10:0000001a r9:843dbc00 r8:20000040 r7:00000000 r6:0000000a r5:00000074 r4:843dec50 [<80209d24>] (fpa_set) from [<8020a468>] (copy_regset_from_user include/linux/regset.h:337 [inline]) [<80209d24>] (fpa_set) from [<8020a468>] (arch_ptrace+0x334/0x424 arch/arm/kernel/ptrace.c:762) r6:0000000a r5:0000000c r4:20000040 [<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 r6:0000000a r5:0000000f r4:843dec00 [<80252da4>] (sys_ptrace) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfdb5fa8 to 0xdfdb5ff0) 5fa0: 00000000 00000000 0000000f 000000b7 0000000a 20000040 5fc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76b150bc 5fe0: 76b14ec0 76b14eb0 00018af0 00133450 r10:0000001a r9:843dbc00 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