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: 8825 Comm: syz.0.1263 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 : [<819c4bc0>] lr : [<802be434>] psr: 60000013 sp : dfd3dd90 ip : dfd3dcd0 fp : dfd3ddb4 r10: 81a00568 r9 : 00000078 r8 : 84350050 r7 : dde90740 r6 : 00000000 r5 : 00000074 r4 : 00000050 r3 : 84776000 r2 : 00000000 r1 : 00000000 r0 : 00000066 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 85aede00 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 84776000 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 84350000 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 0xdfd3c000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2787 Register r12 information: 2-page vmalloc region starting at 0xdfd3c000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2787 Process syz.0.1263 (pid: 8825, stack limit = 0xdfd3c000) Stack: (0xdfd3dd90 to 0xdfd3e000) dd80: 82061520 82032f20 82048384 00000050 dda0: 00000074 00000078 dfd3dde4 dfd3ddb8 804d3fdc 819c4b34 00000074 dfd3ddc8 ddc0: 80214800 84350050 00000074 00000000 843500c4 dde90740 dfd3de1c dfd3dde8 dde0: 80512dbc 804d3f10 00000074 20000084 dfd3de0c 84350050 00000074 20000084 de00: 00000074 81a005a0 00000078 81a00568 dfd3de4c dfd3de20 80209db4 80512b40 de20: dfd3de64 82e5e880 00000064 dfd3de2c dfd3de2c 80209d24 84350000 20000084 de40: dfd3def4 dfd3de50 80253634 80209d30 00000000 20000000 20000000 81a0057c de60: 819e9844 00000000 dfd3deb4 dfd3de78 8020d0cc 8020c034 824bd180 00000000 de80: 8027fa10 00000000 00000000 00000000 00000000 00000000 00000000 00000000 dea0: 00000000 84776000 dfd3dedc dfd3deb8 8027e354 802af5ec 00000000 00000000 dec0: dfd3deec 8ea2d02b 84350000 20000080 00004202 00000002 00000000 20000080 dee0: 84776000 0000001a dfd3df6c dfd3def8 8020a1e4 8025332c 84350000 84350884 df00: dfd3df1c dfd3df10 819e9cf0 8027c778 dfd3df6c dfd3df20 802813ec 819e9ccc df20: dfd3df54 00000000 8027e354 60000013 81996a50 819adcd4 dfd3df54 8ea2d02b df40: 00004205 84350000 00004205 8ea2d02b 84350000 00004205 00000002 00000000 df60: dfd3dfa4 dfd3df70 80252fdc 8020a140 80202cc0 8ea2d02b dfd3dfac 00000000 df80: 00000000 002862f4 0000001a 8020029c 84776000 0000001a 00000000 dfd3dfa8 dfa0: 80200060 80252db0 00000000 00000000 00004205 0000055a 00000002 20000080 dfc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76bfd0bc dfe0: 76bfcec0 76bfceb0 00018af0 00133450 60000010 00004205 00000000 00000000 Call trace: [<819c4b28>] (usercopy_abort) from [<804d3fdc>] (__check_heap_object+0xd8/0xf4 mm/slub.c:5651) [<804d3f04>] (__check_heap_object) from [<80512dbc>] (check_heap_object mm/usercopy.c:196 [inline]) [<804d3f04>] (__check_heap_object) from [<80512dbc>] (__check_object_size mm/usercopy.c:251 [inline]) [<804d3f04>] (__check_heap_object) from [<80512dbc>] (__check_object_size+0x288/0x304 mm/usercopy.c:213) r8:dde90740 r7:843500c4 r6:00000000 r5:00000074 r4:84350050 [<80512b34>] (__check_object_size) from [<80209db4>] (check_object_size include/linux/thread_info.h:228 [inline]) [<80512b34>] (__check_object_size) from [<80209db4>] (__copy_from_user include/linux/uaccess.h:110 [inline]) [<80512b34>] (__check_object_size) from [<80209db4>] (user_regset_copyin include/linux/regset.h:268 [inline]) [<80512b34>] (__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 r4:84350050 [<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 r5:84350000 r4:80209d24 [<80253320>] (ptrace_request) from [<8020a1e4>] (arch_ptrace+0xb0/0x424 arch/arm/kernel/ptrace.c:818) r10:0000001a r9:84776000 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 r4:84350000 [<80252da4>] (sys_ptrace) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfd3dfa8 to 0xdfd3dff0) dfa0: 00000000 00000000 00004205 0000055a 00000002 20000080 dfc0: 00000000 00000000 002862f4 0000001a 00000000 00006364 003d0f00 76bfd0bc dfe0: 76bfcec0 76bfceb0 00018af0 00133450 r10:0000001a r9:84776000 r8:8020029c r7:0000001a r6:002862f4 r5:00000000 r4:00000000 Code: e3010524 e3480206 e58dc000 ebfff265 (e7f001f2) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: e3010524 movw r0, #5412 @ 0x1524 4: e3480206 movt r0, #33286 @ 0x8206 8: e58dc000 str ip, [sp] c: ebfff265 bl 0xffffc9a8 * 10: e7f001f2 udf #18 <-- trapping instruction