8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 0000000e when read [0000000e] *pgd=85a78003, *pmd=df80c003 Internal error: Oops: 205 [#1] SMP ARM Modules linked in: CPU: 1 UID: 0 PID: 32351 Comm: syz.1.9644 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 : ead75e18 ip : ead75dd8 fp : ead75e34 r10: 84d1fb80 r9 : 00000000 r8 : 80000001 r7 : ead75e50 r6 : 00000000 r5 : 84557100 r4 : 84b2f600 r3 : 00000001 r2 : 00000000 r1 : 854c3d40 r0 : 00000000 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 852978c0 DAC: 00000000 Register r0 information: NULL pointer Register r1 information: slab kmalloc-64 start 854c3d40 pointer offset 0 size 64 Register r2 information: NULL pointer Register r3 information: non-paged memory Register r4 information: slab io_kiocb start 84b2f600 pointer offset 0 size 192 Register r5 information: slab kmalloc-2k start 84557000 pointer offset 256 size 2048 Register r6 information: NULL pointer Register r7 information: 2-page vmalloc region starting at 0xead74000 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 84d1fb80 pointer offset 0 size 576 Register r11 information: 2-page vmalloc region starting at 0xead74000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Register r12 information: 2-page vmalloc region starting at 0xead74000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2844 Process syz.1.9644 (pid: 32351, stack limit = 0xead74000) Stack: (0xead75e18 to 0xead76000) 5e00: 84b2f600 854dff00 5e20: 00000000 00000040 ead75e84 ead75e38 80892d3c 808899cc 8057abbc 8030cb0c 5e40: 84b2f600 00000001 01b2f600 00000000 00000000 3e61534c 80886a40 84b2f600 5e60: 81cf0bd4 00000000 80000001 81cf0b5c 0000000a 84ac6000 ead75ebc ead75e88 5e80: 80886df4 80892b18 00000000 00000022 00000000 84557000 84b2f66c 84b2f600 5ea0: 8b480000 00000000 00000000 84ac6000 ead75f14 ead75ec0 808877a8 80886b7c 5ec0: 8088e164 81a4bdf8 00000000 00000000 00000001 00000001 81cf0b5c 00000001 5ee0: 84557000 3e61534c 854f96c0 00000000 84557000 000027e2 854f96c0 00000000 5f00: 84ac6000 00000000 ead75fa4 ead75f18 80888250 808875a8 ecac8b10 84557040 5f20: 00000000 00000000 81a4fbd0 81a4faa0 ead75f54 ead75f40 8026b438 8029ce1c 5f40: ead75fb0 40000000 ead75f84 ead75f58 802229dc 8026b3f4 00000000 8281d05c 5f60: ead75fb0 0014c490 ecac8b10 80222930 00000000 3e61534c ead75fac 00000000 5f80: 00000000 002e630c 000001aa 8020029c 84ac6000 000001aa 00000000 ead75fa8 5fa0: 80200060 80888124 00000000 00000000 00000006 000027e2 00000000 00000000 5fc0: 00000000 00000000 002e630c 000001aa 002d0000 00000000 00006364 76bd00bc 5fe0: 76bcfec0 76bcfeb0 0001939c 00131f30 60000010 00000006 00000000 00000000 Call trace: [<808899c0>] (io_buffer_select) from [<80892d3c>] (io_recvmsg+0x230/0x420 io_uring/net.c:988) r7:00000040 r6:00000000 r5:854dff00 r4:84b2f600 [<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) r10:84ac6000 r9:0000000a r8:81cf0b5c r7:80000001 r6:00000000 r5:81cf0bd4 r4:84b2f600 [<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) r10:84ac6000 r9:00000000 r8:00000000 r7:8b480000 r6:84b2f600 r5:84b2f66c r4:84557000 [<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 r9:84ac6000 r8:00000000 r7:854f96c0 r6:000027e2 r5:84557000 r4:00000000 [<80888118>] (sys_io_uring_enter) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xead75fa8 to 0xead75ff0) 5fa0: 00000000 00000000 00000006 000027e2 00000000 00000000 5fc0: 00000000 00000000 002e630c 000001aa 002d0000 00000000 00006364 76bd00bc 5fe0: 76bcfec0 76bcfeb0 0001939c 00131f30 r10:000001aa r9:84ac6000 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