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: 6814 Comm: syz.2.789 Not tainted 6.12.0-rc7-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 : e0101d90 ip : e0101cd0 fp : e0101db4 r10: 81a0056c r9 : 00000078 r8 : 849fbc50 r7 : dde9f6e0 r6 : 00000000 r5 : 00000074 r4 : 00000050 r3 : 849fe000 r2 : 00000000 r1 : 00000000 r0 : 00000066 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 851cb9c0 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 849fe000 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 849fbc00 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 0xe0100000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2786 Register r12 information: 2-page vmalloc region starting at 0xe0100000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2786 Process syz.2.789 (pid: 6814, stack limit = 0xe0100000) Stack: (0xe0101d90 to 0xe0102000) 1d80: 8205c004 8202d9f8 82043048 00000050 1da0: 00000074 00000078 e0101de4 e0101db8 804cf8f8 819a397c 00000074 e0101dc8 1dc0: 802147e0 849fbc50 00000074 00000000 849fbcc4 dde9f6e0 e0101e1c e0101de8 1de0: 8050e7bc 804cf82c 00000074 20000084 e0101e0c 849fbc50 00000074 20000084 1e00: 00000074 81a005a4 00000078 81a0056c e0101e4c e0101e20 80209d94 8050e540 1e20: 849fe000 00000001 80284a58 8260ca7c 849f8594 80209d04 849fbc00 20000084 1e40: e0101ef4 e0101e50 80252ed0 80209d10 00000000 20000000 20000000 81a00580 1e60: 819c893c 00000000 e0101eb4 e0101e78 8020d0ac 8020c014 824bc400 00000000 1e80: 8027eba4 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1ea0: 00000000 849fe000 e0101edc e0101eb8 8027d3d4 802ae5dc 82f6c13c ffffffff 1ec0: e0101eec 785889ba 849fbc00 20000080 00004202 00000002 00000000 20000080 1ee0: 849fe000 0000001a e0101f6c e0101ef8 8020a1c4 80252bc8 849fbc00 849fc484 1f00: e0101f1c e0101f10 819c8de8 8027b950 e0101f6c e0101f20 80280564 819c8dc4 1f20: e0101f54 00000000 8027d3d4 60000013 819758d0 8198cb54 e0101f54 785889ba 1f40: 849fbc00 00004205 849fbc00 785889ba 00004205 849fbc00 00000002 00000000 1f60: e0101fa4 e0101f70 80252874 8020a120 80202cc0 785889ba e0101fac 00000000 1f80: 00000000 002862f4 0000001a 8020029c 849fe000 0000001a 00000000 e0101fa8 1fa0: 80200060 80252648 00000000 00000000 00004205 000003b3 00000002 20000080 1fc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76b3e0bc 1fe0: 76b3dec0 76b3deb0 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:dde9f6e0 r7:849fbcc4 r6:00000000 r5:00000074 r4:849fbc50 [<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) r10:81a0056c r9:00000078 r8:81a005a4 r7:00000074 r6:20000084 r5:00000074 r4:849fbc50 [<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 r5:849fbc00 r4:80209d04 [<80252bbc>] (ptrace_request) from [<8020a1c4>] (arch_ptrace+0xb0/0x424 arch/arm/kernel/ptrace.c:818) r10:0000001a r9:849fe000 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 r5:849fbc00 r4:00004205 [<8025263c>] (sys_ptrace) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xe0101fa8 to 0xe0101ff0) 1fa0: 00000000 00000000 00004205 000003b3 00000002 20000080 1fc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76b3e0bc 1fe0: 76b3dec0 76b3deb0 00018af0 00133450 r10:0000001a r9:849fe000 r8:8020029c r7:0000001a r6:002862f4 r5:00000000 r4:00000000 Code: e30c0008 e3480205 e58dc000 ebfff273 (e7f001f2) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: e30c0008 movw r0, #49160 @ 0xc008 4: e3480205 movt r0, #33285 @ 0x8205 8: e58dc000 str ip, [sp] c: ebfff273 bl 0xffffc9e0 * 10: e7f001f2 udf #18 <-- trapping instruction