Unable to handle kernel NULL pointer dereference at virtual address 0000000e when read [0000000e] *pgd=84797003, *pmd=df777003 Internal error: Oops: 205 [#1] SMP ARM Modules linked in: CPU: 1 UID: 0 PID: 3105 Comm: syz-executor192 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 : [<81a4be54>] psr: 20000013 sp : df985e18 ip : df985dd8 fp : df985e34 r10: 837a6c80 r9 : 00000000 r8 : 80000001 r7 : df985e50 r6 : 00000000 r5 : 841f2900 r4 : 84799000 r3 : 00000001 r2 : 00000000 r1 : 846eb500 r0 : 00000000 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 84731880 DAC: 00000000 Register r0 information: NULL pointer Register r1 information: slab kmalloc-64 start 846eb500 pointer offset 0 size 64 Register r2 information: NULL pointer Register r3 information: non-paged memory Register r4 information: slab io_kiocb start 84799000 pointer offset 0 size 192 Register r5 information: slab kmalloc-2k start 841f2800 pointer offset 256 size 2048 Register r6 information: NULL pointer Register r7 information: 2-page vmalloc region starting at 0xdf984000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Register r8 information: non-slab/vmalloc memory Register r9 information: NULL pointer Register r10 information: slab sock_inode_cache start 837a6c80 pointer offset 0 size 576 Register r11 information: 2-page vmalloc region starting at 0xdf984000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Register r12 information: 2-page vmalloc region starting at 0xdf984000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Process syz-executor192 (pid: 3105, stack limit = 0xdf984000) Stack: (0xdf985e18 to 0xdf986000) 5e00: 84799000 8466a500 5e20: 00000000 00000040 df985e84 df985e38 80892d3c 808899cc 8057abbc 8030cb0c 5e40: 84799000 00000001 01799000 00000000 00000000 c8c55b45 80886a40 84799000 5e60: 81cf0bd4 00000000 80000001 81cf0b5c 0000000a 8402bc00 df985ebc df985e88 5e80: 80886df4 80892b18 00000000 00000000 00000000 841f2800 8479906c 84799000 5ea0: 848c0000 00000000 00000000 8402bc00 df985f14 df985ec0 808877a8 80886b7c 5ec0: 8088e164 81a4bdf8 8479adb8 84731888 00000001 00000001 81cf0b5c 00000001 5ee0: 841f2800 c8c55b45 84786240 00000000 841f2800 000027e2 84786240 00000000 5f00: 8402bc00 00000000 df985fa4 df985f18 80888250 808875a8 df985f74 841f2840 5f20: 00000000 00000000 df985fac df985f38 8022b8b8 8046ec28 df985f64 df985f48 5f40: 8057a6bc 84460c00 00000000 8281d1f0 00000a0f 76f4a000 df985fb0 80234108 5f60: 00000000 000f4240 df985fac df985f78 8023478c c8c55b45 000000c0 00000000 5f80: 00000000 0008e068 000001aa 8020029c 8402bc00 000001aa 00000000 df985fa8 5fa0: 80200060 80888124 00000000 00000000 00000003 000027e2 00000000 00000000 5fc0: 00000000 00000000 0008e068 000001aa 00000001 00000000 000f4240 00000000 5fe0: 7ef9ac70 7ef9ac60 0001088c 0002f900 40000010 00000003 00000000 00000000 Call trace: [<808899c0>] (io_buffer_select) from [<80892d3c>] (io_recvmsg+0x230/0x420 io_uring/net.c:988) r7:00000040 r6:00000000 r5:8466a500 r4:84799000 [<80892b0c>] (io_recvmsg) from [<80886df4>] (__io_issue_sqe io_uring/io_uring.c:1740 [inline]) [<80892b0c>] (io_recvmsg) from [<80886df4>] (io_issue_sqe+0x284/0x658 io_uring/io_uring.c:1759) r10:8402bc00 r9:0000000a r8:81cf0b5c r7:80000001 r6:00000000 r5:81cf0bd4 r4:84799000 [<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) r10:8402bc00 r9:00000000 r8:00000000 r7:848c0000 r6:84799000 r5:8479906c r4:841f2800 [<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 r9:8402bc00 r8:00000000 r7:84786240 r6:000027e2 r5:841f2800 r4:00000000 [<80888118>] (sys_io_uring_enter) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdf985fa8 to 0xdf985ff0) 5fa0: 00000000 00000000 00000003 000027e2 00000000 00000000 5fc0: 00000000 00000000 0008e068 000001aa 00000001 00000000 000f4240 00000000 5fe0: 7ef9ac70 7ef9ac60 0001088c 0002f900 r10:000001aa r9:8402bc00 r8:8020029c r7:000001aa r6:0008e068 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