8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 0000000e when read [0000000e] *pgd=8542a003, *pmd=dfb62003 Internal error: Oops: 205 [#1] SMP ARM Modules linked in: CPU: 1 UID: 0 PID: 8377 Comm: syz.1.1131 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 : [<80889aa8>] lr : [<81a4c134>] psr: 20000013 sp : dfabde00 ip : dfabddc0 fp : dfabde1c r10: 00000040 r9 : 80000001 r8 : 00000000 r7 : dfabde40 r6 : 00000000 r5 : 87f63900 r4 : 852d4300 r3 : 00000001 r2 : 00000000 r1 : 8539f600 r0 : 00000000 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 8539fe80 DAC: 00000000 Register r0 information: NULL pointer Register r1 information: slab kmalloc-64 start 8539f600 pointer offset 0 size 64 Register r2 information: NULL pointer Register r3 information: non-paged memory Register r4 information: slab io_kiocb start 852d4300 pointer offset 0 size 192 Register r5 information: slab kmalloc-2k start 87f63800 pointer offset 256 size 2048 Register r6 information: NULL pointer Register r7 information: 2-page vmalloc region starting at 0xdfabc000 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 0xdfabc000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Register r12 information: 2-page vmalloc region starting at 0xdfabc000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Process syz.1.1131 (pid: 8377, stack limit = 0xdfabc000) Stack: (0xdfabde00 to 0xdfabe000) de00: 8359f400 852d4300 853a9a00 80000001 dfabde84 dfabde20 80893310 80889a64 de20: dfabde4c dfabde30 8089ecc4 8050a4c4 00010001 00000001 8057abbc 00000000 de40: 00000002 00000003 852d4300 80000001 dfabde84 9641a07a 80886ad8 852d4300 de60: 81cf0ca0 00000000 80000001 81cf0b5c 0000001b 853e3c00 dfabdebc dfabde88 de80: 80886c70 80892fd0 852d46c0 852d4780 852d4840 87f63800 852d436c 852d4300 dea0: 88540000 00000000 00000000 853e3c00 dfabdf14 dfabdec0 80887840 80886c14 dec0: 8088e1fc 81a4c0d8 dfabdf24 dfabded8 00000001 00000001 81cf0b5c 00000001 dee0: 87f63800 9641a07a 85181300 00000000 87f63800 00005b43 85181300 00000000 df00: 853e3c00 00000000 dfabdfa4 dfabdf18 808882e8 80887640 ecac8b10 87f63840 df20: 00000000 00000000 81a4feb0 81a4fd80 dfabdf54 dfabdf40 8026b438 8029ce1c df40: dfabdfb0 40000000 dfabdf84 dfabdf58 802229dc 8026b3f4 00000000 8281d05c df60: dfabdfb0 0014c490 ecac8b10 80222930 00000000 9641a07a dfabdfac 00000000 df80: 00000000 002e630c 000001aa 8020029c 853e3c00 000001aa 00000000 dfabdfa8 dfa0: 80200060 808881bc 00000000 00000000 00000004 00005b43 00000000 00000000 dfc0: 00000000 00000000 002e630c 000001aa 002d0000 00000000 00006364 76bdb0bc dfe0: 76bdaec0 76bdaeb0 0001939c 00131f30 60000010 00000004 00000000 00000000 Call trace: [<80889a58>] (io_buffer_select) from [<80893310>] (io_recv_buf_select io_uring/net.c:1098 [inline]) [<80889a58>] (io_buffer_select) from [<80893310>] (io_recv+0x34c/0x46c io_uring/net.c:1138) r7:80000001 r6:853a9a00 r5:852d4300 r4:8359f400 [<80892fc4>] (io_recv) from [<80886c70>] (__io_issue_sqe io_uring/io_uring.c:1740 [inline]) [<80892fc4>] (io_recv) from [<80886c70>] (io_issue_sqe+0x68/0x658 io_uring/io_uring.c:1759) r10:853e3c00 r9:0000001b r8:81cf0b5c r7:80000001 r6:00000000 r5:81cf0ca0 r4:852d4300 [<80886c08>] (io_issue_sqe) from [<80887840>] (io_queue_sqe io_uring/io_uring.c:1975 [inline]) [<80886c08>] (io_issue_sqe) from [<80887840>] (io_submit_sqe io_uring/io_uring.c:2231 [inline]) [<80886c08>] (io_issue_sqe) from [<80887840>] (io_submit_sqes+0x20c/0x938 io_uring/io_uring.c:2348) r10:853e3c00 r9:00000000 r8:00000000 r7:88540000 r6:852d4300 r5:852d436c r4:87f63800 [<80887634>] (io_submit_sqes) from [<808882e8>] (__do_sys_io_uring_enter io_uring/io_uring.c:3408 [inline]) [<80887634>] (io_submit_sqes) from [<808882e8>] (sys_io_uring_enter+0x138/0x780 io_uring/io_uring.c:3342) r10:00000000 r9:853e3c00 r8:00000000 r7:85181300 r6:00005b43 r5:87f63800 r4:00000000 [<808881b0>] (sys_io_uring_enter) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfabdfa8 to 0xdfabdff0) dfa0: 00000000 00000000 00000004 00005b43 00000000 00000000 dfc0: 00000000 00000000 002e630c 000001aa 002d0000 00000000 00006364 76bdb0bc dfe0: 76bdaec0 76bdaeb0 0001939c 00131f30 r10:000001aa r9:853e3c00 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