8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 0000000e when read [0000000e] *pgd=8559e003, *pmd=df58c003 Internal error: Oops: 205 [#1] SMP ARM Modules linked in: CPU: 1 UID: 0 PID: 11418 Comm: syz.1.1980 Not tainted 6.15.0-rc6-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 : [<80889b04>] lr : [<81a4c354>] psr: 20000013 sp : dff99de8 ip : dff99da8 fp : dff99e04 r10: 84c15900 r9 : 00000000 r8 : 80000001 r7 : dff99e20 r6 : 00000000 r5 : 84b1f900 r4 : 8559db40 r3 : 00000001 r2 : 00000000 r1 : 8607a040 r0 : 00000000 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 8511efc0 DAC: 00000000 Register r0 information: NULL pointer Register r1 information: slab kmalloc-64 start 8607a040 pointer offset 0 size 64 Register r2 information: NULL pointer Register r3 information: non-paged memory Register r4 information: slab io_kiocb start 8559db40 pointer offset 0 size 192 Register r5 information: slab kmalloc-2k start 84b1f800 pointer offset 256 size 2048 Register r6 information: NULL pointer Register r7 information: 2-page vmalloc region starting at 0xdff98000 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 84c15900 pointer offset 0 size 576 Register r11 information: 2-page vmalloc region starting at 0xdff98000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Register r12 information: 2-page vmalloc region starting at 0xdff98000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Process syz.1.1980 (pid: 11418, stack limit = 0xdff98000) Stack: (0xdff99de8 to 0xdff9a000) 9de0: 8559db40 83954900 00000000 00000040 dff99e54 dff99e08 9e00: 80892e30 80889ac0 84b1f928 000000e8 858c0000 00000001 01000000 00000000 9e20: 00000000 549c3f58 dff99e54 8559db40 81cf0bd4 00000000 00000000 00000000 9e40: 80000001 838a3c00 dff99e7c dff99e58 808822b4 80892c0c 8559db40 80000001 9e60: 0000000a 81cf0b5c 84777900 00000000 dff99ebc dff99e80 80886d84 80882274 9e80: 00000000 00000000 00000000 81cf0bd4 00000000 84b1f800 8559dbac 8559db40 9ea0: 858c0000 00000000 00000000 838a3c00 dff99f14 dff99ec0 8088789c 80886d48 9ec0: 8088e258 81a4c2f8 81a53ba8 00000000 00000001 00000001 81cf0b5c 00000001 9ee0: 84b1f800 549c3f58 847779c0 00000000 84b1f800 00005b43 847779c0 00000000 9f00: 838a3c00 00000000 dff99fa4 dff99f18 80888344 8088769c 81a53bb0 84b1f840 9f20: 00000000 00000000 dff99fac dff99f38 8022b7f4 81a53b88 8026b438 8029ce24 9f40: dff99fb0 40000000 dff99f84 dff99f58 802229dc 8026b3f4 00000000 8281d05c 9f60: dff99fb0 0014c490 ecac8b10 80222930 00000000 549c3f58 dff99fac 00000000 9f80: 00000000 002e643c 000001aa 8020029c 838a3c00 000001aa 00000000 dff99fa8 9fa0: 80200060 80888218 00000000 00000000 00000005 00005b43 00000000 00000000 9fc0: 00000000 00000000 002e643c 000001aa 002d0000 00000000 00006364 76b4e0bc 9fe0: 76b4dec0 76b4deb0 0001939c 00131f30 60000010 00000005 00000000 00000000 Call trace: [<80889ab4>] (io_buffer_select) from [<80892e30>] (io_recvmsg+0x230/0x420 io_uring/net.c:988) r7:00000040 r6:00000000 r5:83954900 r4:8559db40 [<80892c00>] (io_recvmsg) from [<808822b4>] (__io_issue_sqe+0x4c/0x1c0 io_uring/io_uring.c:1734) r10:838a3c00 r9:80000001 r8:00000000 r7:00000000 r6:00000000 r5:81cf0bd4 r4:8559db40 [<80882268>] (__io_issue_sqe) from [<80886d84>] (io_issue_sqe+0x48/0x59c io_uring/io_uring.c:1757) r9:00000000 r8:84777900 r7:81cf0b5c r6:0000000a r5:80000001 r4:8559db40 [<80886d3c>] (io_issue_sqe) from [<8088789c>] (io_queue_sqe io_uring/io_uring.c:1963 [inline]) [<80886d3c>] (io_issue_sqe) from [<8088789c>] (io_submit_sqe io_uring/io_uring.c:2219 [inline]) [<80886d3c>] (io_issue_sqe) from [<8088789c>] (io_submit_sqes+0x20c/0x938 io_uring/io_uring.c:2336) r10:838a3c00 r9:00000000 r8:00000000 r7:858c0000 r6:8559db40 r5:8559dbac r4:84b1f800 [<80887690>] (io_submit_sqes) from [<80888344>] (__do_sys_io_uring_enter io_uring/io_uring.c:3396 [inline]) [<80887690>] (io_submit_sqes) from [<80888344>] (sys_io_uring_enter+0x138/0x780 io_uring/io_uring.c:3330) r10:00000000 r9:838a3c00 r8:00000000 r7:847779c0 r6:00005b43 r5:84b1f800 r4:00000000 [<8088820c>] (sys_io_uring_enter) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdff99fa8 to 0xdff99ff0) 9fa0: 00000000 00000000 00000005 00005b43 00000000 00000000 9fc0: 00000000 00000000 002e643c 000001aa 002d0000 00000000 00006364 76b4e0bc 9fe0: 76b4dec0 76b4deb0 0001939c 00131f30 r10:000001aa r9:838a3c00 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