8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 0000000e when read [0000000e] *pgd=84b6e003, *pmd=df8d6003 Internal error: Oops: 205 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 5828 Comm: syz.5.102 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 : e01a1e18 ip : e01a1dd8 fp : e01a1e34 r10: 84c17400 r9 : 00000000 r8 : 80000001 r7 : e01a1e50 r6 : 00000000 r5 : 85964100 r4 : 857e1000 r3 : 00000001 r2 : 00000000 r1 : 852818c0 r0 : 00000000 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 8538bbc0 DAC: fffffffd Register r0 information: NULL pointer Register r1 information: slab kmalloc-64 start 852818c0 pointer offset 0 size 64 Register r2 information: NULL pointer Register r3 information: non-paged memory Register r4 information: slab io_kiocb start 857e1000 pointer offset 0 size 192 Register r5 information: slab kmalloc-2k start 85964000 pointer offset 256 size 2048 Register r6 information: NULL pointer Register r7 information: 2-page vmalloc region starting at 0xe01a0000 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 84c17400 pointer offset 0 size 576 Register r11 information: 2-page vmalloc region starting at 0xe01a0000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Register r12 information: 2-page vmalloc region starting at 0xe01a0000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Process syz.5.102 (pid: 5828, stack limit = 0xe01a0000) Stack: (0xe01a1e18 to 0xe01a2000) 1e00: 857e1000 857e6c00 1e20: 00000000 00000040 e01a1e84 e01a1e38 80892d3c 808899cc 8057abbc 8030cb0c 1e40: 857e1000 00000001 017e1000 00000000 00000000 74c50b96 80886a40 857e1000 1e60: 81cf0bd4 00000000 80000001 81cf0b5c 0000000a 85593c00 e01a1ebc e01a1e88 1e80: 80886df4 80892b18 00000000 00000000 00000000 85964000 857e106c 857e1000 1ea0: 85900000 00000000 00000000 85593c00 e01a1f14 e01a1ec0 808877a8 80886b7c 1ec0: 8088e164 81a4bdd8 00000000 00000000 00000001 00000001 81cf0b5c 00000001 1ee0: 85964000 74c50b96 85189b40 00000000 85964000 000027e2 85189b40 00000000 1f00: 85593c00 00000000 e01a1fa4 e01a1f18 80888250 808875a8 ecac8b10 85964040 1f20: 00000000 00000000 81a4fbb0 81a4fa80 e01a1f54 e01a1f40 8026b438 8029ce1c 1f40: e01a1fb0 40000000 e01a1f84 e01a1f58 802229dc 8026b3f4 00000000 8281d05c 1f60: e01a1fb0 0014c490 ecac8b10 80222930 00000000 74c50b96 e01a1fac 00000000 1f80: 00000000 002e630c 000001aa 8020029c 85593c00 000001aa 00000000 e01a1fa8 1fa0: 80200060 80888124 00000000 00000000 00000003 000027e2 00000000 00000000 1fc0: 00000000 00000000 002e630c 000001aa 002d0000 00000000 00006364 76b650bc 1fe0: 76b64ec0 76b64eb0 0001939c 00131f30 60000010 00000003 00000000 00000000 Call trace: [<808899c0>] (io_buffer_select) from [<80892d3c>] (io_recvmsg+0x230/0x420 io_uring/net.c:988) r7:00000040 r6:00000000 r5:857e6c00 r4:857e1000 [<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) r10:85593c00 r9:0000000a r8:81cf0b5c r7:80000001 r6:00000000 r5:81cf0bd4 r4:857e1000 [<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) r10:85593c00 r9:00000000 r8:00000000 r7:85900000 r6:857e1000 r5:857e106c r4:85964000 [<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 r9:85593c00 r8:00000000 r7:85189b40 r6:000027e2 r5:85964000 r4:00000000 [<80888118>] (sys_io_uring_enter) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xe01a1fa8 to 0xe01a1ff0) 1fa0: 00000000 00000000 00000003 000027e2 00000000 00000000 1fc0: 00000000 00000000 002e630c 000001aa 002d0000 00000000 00006364 76b650bc 1fe0: 76b64ec0 76b64eb0 0001939c 00131f30 r10:000001aa r9:85593c00 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