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: 15326 Comm: syz.5.1974 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 : [<819b3340>] lr : [<802be434>] psr: 60000013 sp : ea9edd90 ip : ea9edcd0 fp : ea9eddb4 r10: 81a00568 r9 : 00000078 r8 : 84698050 r7 : dde97d60 r6 : 00000000 r5 : 00000074 r4 : 00000050 r3 : 83514800 r2 : 00000000 r1 : 00000000 r0 : 00000066 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 8547ce80 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 83514800 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 84698000 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 0xea9ec000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2787 Register r12 information: 2-page vmalloc region starting at 0xea9ec000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2787 Process syz.5.1974 (pid: 15326, stack limit = 0xea9ec000) Stack: (0xea9edd90 to 0xea9ee000) dd80: 8205ec8c 820306e8 82045b4c 00000050 dda0: 00000074 00000078 ea9edde4 ea9eddb8 804d1d40 819b32b4 00000074 ea9eddc8 ddc0: 80214800 84698050 00000074 00000000 846980c4 dde97d60 ea9ede1c ea9edde8 dde0: 80510b1c 804d1c74 00000074 20000084 ea9ede0c 84698050 00000074 20000084 de00: 00000074 81a005a0 00000078 81a00568 ea9ede4c ea9ede20 80209db4 805108a0 de20: 83514800 00000001 802856d4 00000008 ddde4340 80209d24 84698000 20000084 de40: ea9edef4 ea9ede50 80253634 80209d30 00000000 20000000 20000000 81a0057c de60: 819d7fc4 00000000 ea9edeb4 ea9ede78 8020d0cc 8020c034 ea9ede9c 00000000 de80: 8027fa10 00000000 00000000 00000000 00000000 00000000 00000000 00000000 dea0: 00000000 83514800 ea9ededc ea9edeb8 8027e354 802af5ec 82e507fc ffffffff dec0: ea9edeec 2441b0a0 84698000 20000080 00004202 00000002 00000000 20000080 dee0: 83514800 0000001a ea9edf6c ea9edef8 8020a1e4 8025332c 84698000 84698884 df00: ea9edf1c ea9edf10 819d8470 8027c778 ea9edf6c ea9edf20 802813ec 819d844c df20: ea9edf54 00000000 8027e354 60000013 819851d0 8199c454 ea9edf54 2441b0a0 df40: 00004205 84698000 00004205 2441b0a0 84698000 00004205 00000002 00000000 df60: ea9edfa4 ea9edf70 80252fdc 8020a140 80202cc0 2441b0a0 ea9edfac 00000000 df80: 00000000 002862f4 0000001a 8020029c 83514800 0000001a 00000000 ea9edfa8 dfa0: 80200060 80252db0 00000000 00000000 00004205 00000130 00000002 20000080 dfc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76b8c0bc dfe0: 76b8bec0 76b8beb0 00018af0 00133450 60000010 00004205 00000000 00000000 Call trace: [<819b32a8>] (usercopy_abort) from [<804d1d40>] (__check_heap_object+0xd8/0xf4 mm/slub.c:5651) [<804d1c68>] (__check_heap_object) from [<80510b1c>] (check_heap_object mm/usercopy.c:196 [inline]) [<804d1c68>] (__check_heap_object) from [<80510b1c>] (__check_object_size mm/usercopy.c:251 [inline]) [<804d1c68>] (__check_heap_object) from [<80510b1c>] (__check_object_size+0x288/0x304 mm/usercopy.c:213) r8:dde97d60 r7:846980c4 r6:00000000 r5:00000074 r4:84698050 [<80510894>] (__check_object_size) from [<80209db4>] (check_object_size include/linux/thread_info.h:228 [inline]) [<80510894>] (__check_object_size) from [<80209db4>] (__copy_from_user include/linux/uaccess.h:110 [inline]) [<80510894>] (__check_object_size) from [<80209db4>] (user_regset_copyin include/linux/regset.h:268 [inline]) [<80510894>] (__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 r4:84698050 [<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 r5:84698000 r4:80209d24 [<80253320>] (ptrace_request) from [<8020a1e4>] (arch_ptrace+0xb0/0x424 arch/arm/kernel/ptrace.c:818) r10:0000001a r9:83514800 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 r4:84698000 [<80252da4>] (sys_ptrace) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xea9edfa8 to 0xea9edff0) dfa0: 00000000 00000000 00004205 00000130 00000002 20000080 dfc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76b8c0bc dfe0: 76b8bec0 76b8beb0 00018af0 00133450 r10:0000001a r9:83514800 r8:8020029c r7:0000001a r6:002862f4 r5:00000000 r4:00000000 Code: e30e0c90 e3480205 e58dc000 ebfff265 (e7f001f2) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: e30e0c90 movw r0, #60560 @ 0xec90 4: e3480205 movt r0, #33285 @ 0x8205 8: e58dc000 str ip, [sp] c: ebfff265 bl 0xffffc9a8 * 10: e7f001f2 udf #18 <-- trapping instruction