8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 0000000e when read [0000000e] *pgd=87ec2003, *pmd=dfbde003 Internal error: Oops: 205 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 6137 Comm: syz.2.594 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 : dff0de00 ip : dff0ddc0 fp : dff0de1c r10: 00000240 r9 : 80000001 r8 : 00000000 r7 : dff0de40 r6 : 00000000 r5 : 85132900 r4 : 84820600 r3 : 00000001 r2 : 00000000 r1 : 854cf540 r0 : 00000000 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 8519acc0 DAC: fffffffd Register r0 information: NULL pointer Register r1 information: slab kmalloc-64 start 854cf540 pointer offset 0 size 64 Register r2 information: NULL pointer Register r3 information: non-paged memory Register r4 information: slab io_kiocb start 84820600 pointer offset 0 size 192 Register r5 information: slab kmalloc-2k start 85132800 pointer offset 256 size 2048 Register r6 information: NULL pointer Register r7 information: 2-page vmalloc region starting at 0xdff0c000 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 0xdff0c000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Register r12 information: 2-page vmalloc region starting at 0xdff0c000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Process syz.2.594 (pid: 6137, stack limit = 0xdff0c000) Stack: (0xdff0de00 to 0xdff0e000) de00: 8373ac80 84820600 85526400 80000001 dff0de84 dff0de20 80893278 808899cc de20: dff0de4c dff0de30 8089ec2c 8050a4c4 00010001 00000001 8057abbc 00000000 de40: 00000000 00000003 84820600 80000001 dff0de84 44e7f82c 80886a40 84820600 de60: 81cf0ca0 00000000 80000001 81cf0b5c 0000001b 87e23000 dff0debc dff0de88 de80: 80886bd8 80892f38 848209c0 84820a80 84820b40 85132800 8482066c 84820600 dea0: 87f40000 00000000 00000000 87e23000 dff0df14 dff0dec0 808877a8 80886b7c dec0: 8088e164 81a4bdd8 00000000 00000000 00000800 00000800 81cf0b5c 00000800 dee0: 85132800 44e7f82c 8465e0c0 00000000 85132800 00003516 8465e0c0 00000000 df00: 87e23000 00000000 dff0dfa4 dff0df18 80888250 808875a8 ecac8b10 85132840 df20: 00000000 00000000 81a4fbb0 81a4fa80 dff0df54 dff0df40 8026b438 8029ce1c df40: dff0dfb0 40000000 dff0df84 dff0df58 802229dc 8026b3f4 00000000 8281d05c df60: dff0dfb0 0014c490 ecac8b10 80222930 00000000 44e7f82c dff0dfac 00000000 df80: 00000000 002e630c 000001aa 8020029c 87e23000 000001aa 00000000 dff0dfa8 dfa0: 80200060 80888124 00000000 00000000 00000004 00003516 00000000 00000000 dfc0: 00000000 00000000 002e630c 000001aa 002d0000 00000000 00006364 76b730bc dfe0: 76b72ec0 76b72eb0 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 r6:85526400 r5:84820600 r4:8373ac80 [<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) r10:87e23000 r9:0000001b r8:81cf0b5c r7:80000001 r6:00000000 r5:81cf0ca0 r4:84820600 [<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) r10:87e23000 r9:00000000 r8:00000000 r7:87f40000 r6:84820600 r5:8482066c r4:85132800 [<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 r9:87e23000 r8:00000000 r7:8465e0c0 r6:00003516 r5:85132800 r4:00000000 [<80888118>] (sys_io_uring_enter) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdff0dfa8 to 0xdff0dff0) dfa0: 00000000 00000000 00000004 00003516 00000000 00000000 dfc0: 00000000 00000000 002e630c 000001aa 002d0000 00000000 00006364 76b730bc dfe0: 76b72ec0 76b72eb0 0001939c 00131f30 r10:000001aa r9:87e23000 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