8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 0000000e when read [0000000e] *pgd=8450f003, *pmd=efdfb003 Internal error: Oops: 205 [#1] SMP ARM Modules linked in: CPU: 0 UID: 0 PID: 28695 Comm: syz.9.3644 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 : [<80889b54>] lr : [<81a4c394>] psr: 20000013 sp : dfd79de8 ip : dfd79da8 fp : dfd79e04 r10: 83598c80 r9 : 00000000 r8 : 80000001 r7 : dfd79e20 r6 : 00000000 r5 : 85e96900 r4 : 85ef4600 r3 : 00000001 r2 : 00000000 r1 : 84e711c0 r0 : 00000000 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 85cc8840 DAC: fffffffd Register r0 information: NULL pointer Register r1 information: slab kmalloc-64 start 84e711c0 pointer offset 0 size 64 Register r2 information: NULL pointer Register r3 information: non-paged memory Register r4 information: slab io_kiocb start 85ef4600 pointer offset 0 size 192 Register r5 information: slab kmalloc-2k start 85e96800 pointer offset 256 size 2048 Register r6 information: NULL pointer Register r7 information: 2-page vmalloc region starting at 0xdfd78000 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 83598c80 pointer offset 0 size 576 Register r11 information: 2-page vmalloc region starting at 0xdfd78000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Register r12 information: 2-page vmalloc region starting at 0xdfd78000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Process syz.9.3644 (pid: 28695, stack limit = 0xdfd78000) Stack: (0xdfd79de8 to 0xdfd7a000) 9de0: 85ef4600 8443eb00 00000000 00000040 dfd79e54 dfd79e08 9e00: 80892e80 80889b10 85e96928 000000e8 85bc0000 00000001 01000000 00000000 9e20: 00000000 cb434a76 dfd79e54 85ef4600 81cf0bd4 00000000 00000000 00000000 9e40: 80000001 84866000 dfd79e7c dfd79e58 80882304 80892c5c 85ef4600 80000001 9e60: 0000000a 81cf0b5c 8442b600 00000000 dfd79ebc dfd79e80 80886dd4 808822c4 9e80: 00000000 00000000 00000000 81cf0bd4 00000000 85e96800 85ef466c 85ef4600 9ea0: 85bc0000 00000000 00000000 84866000 dfd79f14 dfd79ec0 808878ec 80886d98 9ec0: 8088e2a8 81a4c338 dfd79f24 dfd79ed8 00000001 00000001 81cf0b5c 00000001 9ee0: 85e96800 cb434a76 8442b6c0 00000000 85e96800 00005b43 8442b6c0 00000000 9f00: 84866000 00000000 dfd79fa4 dfd79f18 80888394 808876ec ecac8b10 85e96840 9f20: 00000000 00000000 81a50110 81a4ffe0 dfd79f54 dfd79f40 8026b438 8029ce24 9f40: dfd79fb0 40000000 dfd79f84 dfd79f58 802229dc 8026b3f4 00000000 8281d05c 9f60: dfd79fb0 0014c490 ecac8b10 80222930 00000000 cb434a76 dfd79fac 00000000 9f80: 00000000 002e630c 000001aa 8020029c 84866000 000001aa 00000000 dfd79fa8 9fa0: 80200060 80888268 00000000 00000000 00000003 00005b43 00000000 00000000 9fc0: 00000000 00000000 002e630c 000001aa 002d0000 00000000 00006364 76b540bc 9fe0: 76b53ec0 76b53eb0 0001939c 00131f30 60000010 00000003 00000000 00000000 Call trace: [<80889b04>] (io_buffer_select) from [<80892e80>] (io_recvmsg+0x230/0x420 io_uring/net.c:988) r7:00000040 r6:00000000 r5:8443eb00 r4:85ef4600 [<80892c50>] (io_recvmsg) from [<80882304>] (__io_issue_sqe+0x4c/0x1c0 io_uring/io_uring.c:1734) r10:84866000 r9:80000001 r8:00000000 r7:00000000 r6:00000000 r5:81cf0bd4 r4:85ef4600 [<808822b8>] (__io_issue_sqe) from [<80886dd4>] (io_issue_sqe+0x48/0x59c io_uring/io_uring.c:1757) r9:00000000 r8:8442b600 r7:81cf0b5c r6:0000000a r5:80000001 r4:85ef4600 [<80886d8c>] (io_issue_sqe) from [<808878ec>] (io_queue_sqe io_uring/io_uring.c:1963 [inline]) [<80886d8c>] (io_issue_sqe) from [<808878ec>] (io_submit_sqe io_uring/io_uring.c:2219 [inline]) [<80886d8c>] (io_issue_sqe) from [<808878ec>] (io_submit_sqes+0x20c/0x938 io_uring/io_uring.c:2336) r10:84866000 r9:00000000 r8:00000000 r7:85bc0000 r6:85ef4600 r5:85ef466c r4:85e96800 [<808876e0>] (io_submit_sqes) from [<80888394>] (__do_sys_io_uring_enter io_uring/io_uring.c:3396 [inline]) [<808876e0>] (io_submit_sqes) from [<80888394>] (sys_io_uring_enter+0x138/0x780 io_uring/io_uring.c:3330) r10:00000000 r9:84866000 r8:00000000 r7:8442b6c0 r6:00005b43 r5:85e96800 r4:00000000 [<8088825c>] (sys_io_uring_enter) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfd79fa8 to 0xdfd79ff0) 9fa0: 00000000 00000000 00000003 00005b43 00000000 00000000 9fc0: 00000000 00000000 002e630c 000001aa 002d0000 00000000 00006364 76b540bc 9fe0: 76b53ec0 76b53eb0 0001939c 00131f30 r10:000001aa r9:84866000 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