8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 0000000e when read [0000000e] *pgd=85677003, *pmd=df551003 Internal error: Oops: 205 [#1] SMP ARM Modules linked in: CPU: 1 UID: 0 PID: 4010 Comm: syz.0.41 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 : dfc99e00 ip : dfc99dc0 fp : dfc99e1c r10: 00000240 r9 : 80000001 r8 : 00000000 r7 : dfc99e40 r6 : 00000000 r5 : 8496b900 r4 : 8578ec00 r3 : 00000001 r2 : 00000000 r1 : 85606840 r0 : 00000000 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 8567fa80 DAC: 00000000 Register r0 information: NULL pointer Register r1 information: slab kmalloc-64 start 85606840 pointer offset 0 size 64 Register r2 information: NULL pointer Register r3 information: non-paged memory Register r4 information: slab io_kiocb start 8578ec00 pointer offset 0 size 192 Register r5 information: slab kmalloc-2k start 8496b800 pointer offset 256 size 2048 Register r6 information: NULL pointer Register r7 information: 2-page vmalloc region starting at 0xdfc98000 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 0xdfc98000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Register r12 information: 2-page vmalloc region starting at 0xdfc98000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Process syz.0.41 (pid: 4010, stack limit = 0xdfc98000) Stack: (0xdfc99e00 to 0xdfc9a000) 9e00: 84c11680 8578ec00 84b6e800 80000001 dfc99e84 dfc99e20 80893310 80889a64 9e20: dfc99e4c dfc99e30 8089ecc4 8050a4c4 00010001 00000001 8057abbc 00000000 9e40: 00000000 00000005 8578ec00 80000001 dfc99e84 08f28cec 80886ad8 8578ec00 9e60: 81cf0ca0 00000000 80000001 81cf0b5c 0000001b 83309800 dfc99ebc dfc99e88 9e80: 80886c70 80892fd0 8578f000 8578f0c0 8578f180 8496b800 8578ec6c 8578ec00 9ea0: 85820000 00000000 00000000 83309800 dfc99f14 dfc99ec0 80887840 80886c14 9ec0: 8088e1fc 81a4c0d8 81a53dbc 00000000 00000800 00000800 81cf0b5c 00000800 9ee0: 8496b800 08f28cec 85421900 00000000 8496b800 00003516 85421900 00000000 9f00: 83309800 00000000 dfc99fa4 dfc99f18 808882e8 80887640 ecac8b10 8496b840 9f20: 00000000 00000000 81a4feb0 81a4fd80 dfc99f54 dfc99f40 8026b438 8029ce1c 9f40: dfc99fb0 40000000 dfc99f84 dfc99f58 802229dc 8026b3f4 00000000 8281d05c 9f60: dfc99fb0 0014c490 ecac8b10 80222930 00000000 08f28cec dfc99fac 00000000 9f80: 00000000 002e643c 000001aa 8020029c 83309800 000001aa 00000000 dfc99fa8 9fa0: 80200060 808881bc 00000000 00000000 00000006 00003516 00000000 00000000 9fc0: 00000000 00000000 002e643c 000001aa 002d0000 00000000 00006364 76b040bc 9fe0: 76b03ec0 76b03eb0 0001939c 00131f30 60000010 00000006 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 r6:84b6e800 r5:8578ec00 r4:84c11680 [<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) r10:83309800 r9:0000001b r8:81cf0b5c r7:80000001 r6:00000000 r5:81cf0ca0 r4:8578ec00 [<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) r10:83309800 r9:00000000 r8:00000000 r7:85820000 r6:8578ec00 r5:8578ec6c r4:8496b800 [<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 r9:83309800 r8:00000000 r7:85421900 r6:00003516 r5:8496b800 r4:00000000 [<808881b0>] (sys_io_uring_enter) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfc99fa8 to 0xdfc99ff0) 9fa0: 00000000 00000000 00000006 00003516 00000000 00000000 9fc0: 00000000 00000000 002e643c 000001aa 002d0000 00000000 00006364 76b040bc 9fe0: 76b03ec0 76b03eb0 0001939c 00131f30 r10:000001aa r9:83309800 r8:8020029c r7:000001aa r6:002e643c 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