8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 0000000e when read [0000000e] *pgd=85507003, *pmd=dfa90003 Internal error: Oops: 205 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 5390 Comm: syz.2.308 Not tainted 6.15.0-rc5-syzkaller #0 PREEMPT Hardware name: ARM-Versatile Express PC is at io_ring_buffer_select io_uring/kbuf.c:163 [inline] PC is at io_buffer_select+0x50/0x18c io_uring/kbuf.c:207 LR is at rcu_read_unlock include/linux/rcupdate.h:873 [inline] LR is at xa_load+0x68/0xa4 lib/xarray.c:1621 pc : [<80889a10>] lr : [<81a4be34>] psr: 20000013 sp : e0715e00 ip : e0715dc0 fp : e0715e1c r10: 00000240 r9 : 80000001 r8 : 00000000 r7 : e0715e40 r6 : 00000000 r5 : 8467f900 r4 : 857b7000 r3 : 00000001 r2 : 00000000 r1 : 851d4a40 r0 : 00000000 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 853a3e00 DAC: fffffffd Register r0 information: NULL pointer Register r1 information: slab kmalloc-64 start 851d4a40 pointer offset 0 size 64 Register r2 information: NULL pointer Register r3 information: non-paged memory Register r4 information: slab io_kiocb start 857b7000 pointer offset 0 size 192 Register r5 information: slab kmalloc-2k start 8467f800 pointer offset 256 size 2048 Register r6 information: NULL pointer Register r7 information: 2-page vmalloc region starting at 0xe0714000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Register r8 information: NULL pointer Register r9 information: non-slab/vmalloc memory Register r10 information: non-paged memory Register r11 information: 2-page vmalloc region starting at 0xe0714000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Register r12 information: 2-page vmalloc region starting at 0xe0714000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Process syz.2.308 (pid: 5390, stack limit = 0xe0714000) Stack: (0xe0715e00 to 0xe0716000) 5e00: 84cc4280 857b7000 85654d00 80000001 e0715e84 e0715e20 80893278 808899cc 5e20: e0715e4c e0715e30 8089ec2c 8050a4c4 00010001 00000001 8057abbc 00000000 5e40: 00000000 00000003 857b7000 80000001 e0715e84 d6a8f705 80886a40 857b7000 5e60: 81cf0ca0 00000000 80000001 81cf0b5c 0000001b 84486000 e0715ebc e0715e88 5e80: 80886bd8 80892f38 857b73c0 857b7480 857b7540 8467f800 857b706c 857b7000 5ea0: 85900000 00000000 00000000 84486000 e0715f14 e0715ec0 808877a8 80886b7c 5ec0: 8088e164 81a4bdd8 e0715f24 e0715ed8 00000800 00000800 81cf0b5c 00000800 5ee0: 8467f800 d6a8f705 8518bc00 00000000 8467f800 00003516 8518bc00 00000000 5f00: 84486000 00000000 e0715fa4 e0715f18 80888250 808875a8 ecac8b10 8467f840 5f20: 00000000 00000000 81a4fbb0 81a4fa80 e0715f54 e0715f40 8026b438 8029ce1c 5f40: e0715fb0 40000000 e0715f84 e0715f58 802229dc 8026b3f4 00000000 8281d05c 5f60: e0715fb0 0014c490 ecac8b10 80222930 00000000 d6a8f705 e0715fac 00000000 5f80: 00000000 002e630c 000001aa 8020029c 84486000 000001aa 00000000 e0715fa8 5fa0: 80200060 80888124 00000000 00000000 00000004 00003516 00000000 00000000 5fc0: 00000000 00000000 002e630c 000001aa 002d0000 00000000 00006364 76bf80bc 5fe0: 76bf7ec0 76bf7eb0 0001939c 00131f30 60000010 00000004 00000000 00000000 Call trace: [<808899c0>] (io_buffer_select) from [<80893278>] (io_recv_buf_select io_uring/net.c:1098 [inline]) [<808899c0>] (io_buffer_select) from [<80893278>] (io_recv+0x34c/0x46c io_uring/net.c:1138) r7:80000001 r6:85654d00 r5:857b7000 r4:84cc4280 [<80892f2c>] (io_recv) from [<80886bd8>] (__io_issue_sqe io_uring/io_uring.c:1740 [inline]) [<80892f2c>] (io_recv) from [<80886bd8>] (io_issue_sqe+0x68/0x658 io_uring/io_uring.c:1759) r10:84486000 r9:0000001b r8:81cf0b5c r7:80000001 r6:00000000 r5:81cf0ca0 r4:857b7000 [<80886b70>] (io_issue_sqe) from [<808877a8>] (io_queue_sqe io_uring/io_uring.c:1975 [inline]) [<80886b70>] (io_issue_sqe) from [<808877a8>] (io_submit_sqe io_uring/io_uring.c:2231 [inline]) [<80886b70>] (io_issue_sqe) from [<808877a8>] (io_submit_sqes+0x20c/0x938 io_uring/io_uring.c:2348) r10:84486000 r9:00000000 r8:00000000 r7:85900000 r6:857b7000 r5:857b706c r4:8467f800 [<8088759c>] (io_submit_sqes) from [<80888250>] (__do_sys_io_uring_enter io_uring/io_uring.c:3408 [inline]) [<8088759c>] (io_submit_sqes) from [<80888250>] (sys_io_uring_enter+0x138/0x780 io_uring/io_uring.c:3342) r10:00000000 r9:84486000 r8:00000000 r7:8518bc00 r6:00003516 r5:8467f800 r4:00000000 [<80888118>] (sys_io_uring_enter) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xe0715fa8 to 0xe0715ff0) 5fa0: 00000000 00000000 00000004 00003516 00000000 00000000 5fc0: 00000000 00000000 002e630c 000001aa 002d0000 00000000 00006364 76bf80bc 5fe0: 76bf7ec0 76bf7eb0 0001939c 00131f30 r10:000001aa r9:84486000 r8:8020029c r7:000001aa r6:002e630c r5:00000000 r4:00000000 Code: e3130001 0a00002f e5910000 e1d120be (e1d030be) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: e3130001 tst r3, #1 4: 0a00002f beq 0xc8 8: e5910000 ldr r0, [r1] c: e1d120be ldrh r2, [r1, #14] * 10: e1d030be ldrh r3, [r0, #14] <-- trapping instruction