memory leak in getname_flags ( 5.9.0-rc5)

From: \xcH3332\
Date: Thu Sep 17 2020 - 10:31:04 EST

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Syzkaller hit 'memory leak in getname_flags' bug.

5.9.0-rc5

2020/09/17 10:31:39 executed programs: 195
2020/09/17 10:31:45 executed programs: 204
2020/09/17 10:31:50 executed programs: 226
2020/09/17 10:31:56 executed programs: 239
BUG: memory leak
unreferenced object 0xffff8ba9f42fa000 (size 4096):
comm "syz-executor.4", pid 5686, jiffies 4295939335 (age 12.397s)
hex dump (first 32 bytes):
20 a0 2f f4 a9 8b ff ff 40 02 00 20 00 00 00 00 ./.....@.. ....
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000084fbe16c>] getname_flags+0x57/0x260
[<00000000a25b6483>] __io_openat_prep+0x76/0x100
[<0000000030fd3f89>] io_openat2_prep.part.0+0x5b/0xb0
[<00000000e274bfc6>] io_issue_sqe+0x445/0x1940
[<00000000bad7fba6>] __io_queue_sqe+0x189/0x540
[<000000000d09a5ef>] io_queue_sqe+0x28f/0x440
[<00000000c36c4e95>] io_submit_sqes+0x7e9/0xa90
[<00000000a15f6a28>] __x64_sys_io_uring_enter+0x23e/0x350
[<00000000449792f4>] do_syscall_64+0x33/0x40
[<00000000bdacf1c3>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Syzkaller reproducer:
# {Threaded:true Collide:true Repeat:true RepeatTimes:0 Procs:8
Sandbox:none Fault:false FaultCall:-1 FaultNth:0 Leak:true
NetInjection:false NetDevices:true NetReset:true Cgroups:true
BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false USB:false
VhciInjection:false UseTmpDir:true HandleSegv:true Repro:false
Trace:false}
r0 = syz_io_uring_setup(0x5bfa, &(0x7f0000000080)={0x0, 0x0, 0x0, 0x2,
0x0, 0x0, 0x0}, &(0x7f00000a0000)=nil, &(0x7f00000b0000)=nil,
&(0x7f0000000100)=<r1=>0x0, &(0x7f0000000140)=<r2=>0x0)
syz_io_uring_submit(r1, r2,
&(0x7f00000001c0)=@IORING_OP_OPENAT2={0x1c, 0x0, 0x0,
0xffffffffffffff9c, &(0x7f0000000200)={0x42},
&(0x7f0000000240)='./file1\x00', 0x18, 0x0, 0x12345}, 0x0)
io_uring_enter(r0, 0x1, 0x1, 0x1, 0x0, 0x0)

Attachment: syz.config
Description: Binary data

#define _GNU_SOURCE

#include <endian.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>

#define SIZEOF_IO_URING_SQE 64
#define SIZEOF_IO_URING_CQE 16
#define SQ_HEAD_OFFSET 0
#define SQ_TAIL_OFFSET 64
#define SQ_RING_MASK_OFFSET 256
#define SQ_RING_ENTRIES_OFFSET 264
#define SQ_FLAGS_OFFSET 276
#define SQ_DROPPED_OFFSET 272
#define CQ_HEAD_OFFSET 128
#define CQ_TAIL_OFFSET 192
#define CQ_RING_MASK_OFFSET 260
#define CQ_RING_ENTRIES_OFFSET 268
#define CQ_RING_OVERFLOW_OFFSET 284
#define CQ_FLAGS_OFFSET 280
#define CQ_CQES_OFFSET 320

struct io_sqring_offsets {
uint32_t head;
uint32_t tail;
uint32_t ring_mask;
uint32_t ring_entries;
uint32_t flags;
uint32_t dropped;
uint32_t array;
uint32_t resv1;
uint64_t resv2;
};

struct io_cqring_offsets {
uint32_t head;
uint32_t tail;
uint32_t ring_mask;
uint32_t ring_entries;
uint32_t overflow;
uint32_t cqes;
uint64_t resv[2];
};

struct io_uring_params {
uint32_t sq_entries;
uint32_t cq_entries;
uint32_t flags;
uint32_t sq_thread_cpu;
uint32_t sq_thread_idle;
uint32_t features;
uint32_t resv[4];
struct io_sqring_offsets sq_off;
struct io_cqring_offsets cq_off;
};

#define IORING_OFF_SQ_RING 0
#define IORING_OFF_SQES 0x10000000ULL

#define sys_io_uring_setup 425
static long syz_io_uring_setup(volatile long a0, volatile long a1, volatile long a2, volatile long a3, volatile long a4, volatile long a5)
{
uint32_t entries = (uint32_t)a0;
struct io_uring_params* setup_params = (struct io_uring_params*)a1;
void* vma1 = (void*)a2;
void* vma2 = (void*)a3;
void** ring_ptr_out = (void**)a4;
void** sqes_ptr_out = (void**)a5;
uint32_t fd_io_uring = syscall(sys_io_uring_setup, entries, setup_params);
uint32_t sq_ring_sz = setup_params->sq_off.array + setup_params->sq_entries * sizeof(uint32_t);
uint32_t cq_ring_sz = setup_params->cq_off.cqes + setup_params->cq_entries * SIZEOF_IO_URING_CQE;
uint32_t ring_sz = sq_ring_sz > cq_ring_sz ? sq_ring_sz : cq_ring_sz;
*ring_ptr_out = mmap(vma1, ring_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE | MAP_FIXED, fd_io_uring, IORING_OFF_SQ_RING);
uint32_t sqes_sz = setup_params->sq_entries * SIZEOF_IO_URING_SQE;
*sqes_ptr_out = mmap(vma2, sqes_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE | MAP_FIXED, fd_io_uring, IORING_OFF_SQES);
return fd_io_uring;
}

static long syz_io_uring_submit(volatile long a0, volatile long a1, volatile long a2, volatile long a3)
{
char* ring_ptr = (char*)a0;
char* sqes_ptr = (char*)a1;
char* sqe = (char*)a2;
uint32_t sqes_index = (uint32_t)a3;
uint32_t sq_ring_entries = *(uint32_t*)(ring_ptr + SQ_RING_ENTRIES_OFFSET);
uint32_t cq_ring_entries = *(uint32_t*)(ring_ptr + CQ_RING_ENTRIES_OFFSET);
uint32_t sq_array_off = (CQ_CQES_OFFSET + cq_ring_entries * SIZEOF_IO_URING_CQE + 63) & ~63;
if (sq_ring_entries)
sqes_index %= sq_ring_entries;
char* sqe_dest = sqes_ptr + sqes_index * SIZEOF_IO_URING_SQE;
memcpy(sqe_dest, sqe, SIZEOF_IO_URING_SQE);
uint32_t sq_ring_mask = *(uint32_t*)(ring_ptr + SQ_RING_MASK_OFFSET);
uint32_t* sq_tail_ptr = (uint32_t*)(ring_ptr + SQ_TAIL_OFFSET);
uint32_t sq_tail = *sq_tail_ptr & sq_ring_mask;
uint32_t sq_tail_next = *sq_tail_ptr + 1;
uint32_t* sq_array = (uint32_t*)(ring_ptr + sq_array_off);
*(sq_array + sq_tail) = sqes_index;
__atomic_store_n(sq_tail_ptr, sq_tail_next, __ATOMIC_RELEASE);
return 0;
}

#ifndef __NR_io_uring_enter
#define __NR_io_uring_enter 426
#endif

uint64_t r[3] = {0xffffffffffffffff, 0x0, 0x0};

int main(void)
{
syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul);
syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul);
syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul);
intptr_t res = 0;
*(uint32_t*)0x20000084 = 0;
*(uint32_t*)0x20000088 = 0;
*(uint32_t*)0x2000008c = 2;
*(uint32_t*)0x20000090 = 0;
*(uint32_t*)0x20000098 = 0;
*(uint32_t*)0x2000009c = 0;
*(uint32_t*)0x200000a0 = 0;
*(uint32_t*)0x200000a4 = 0;
res = -1;
res = syz_io_uring_setup(0x5bfa, 0x20000080, 0x200a0000, 0x200b0000, 0x20000100, 0x20000140);
if (res != -1) {
r[0] = res;
r[1] = *(uint64_t*)0x20000100;
r[2] = *(uint64_t*)0x20000140;
}
*(uint8_t*)0x200001c0 = 0x1c;
*(uint8_t*)0x200001c1 = 0;
*(uint16_t*)0x200001c2 = 0;
*(uint32_t*)0x200001c4 = 0xffffff9c;
*(uint64_t*)0x200001c8 = 0x20000200;
*(uint64_t*)0x20000200 = 0x42;
*(uint64_t*)0x20000208 = 0;
*(uint64_t*)0x20000210 = 0;
*(uint64_t*)0x200001d0 = 0x20000240;
memcpy((void*)0x20000240, "./file1\000", 8);
*(uint32_t*)0x200001d8 = 0x18;
*(uint32_t*)0x200001dc = 0;
*(uint64_t*)0x200001e0 = 0x12345;
*(uint16_t*)0x200001e8 = 0;
*(uint16_t*)0x200001ea = 0;
*(uint8_t*)0x200001ec = 0;
*(uint8_t*)0x200001ed = 0;
*(uint8_t*)0x200001ee = 0;
*(uint8_t*)0x200001ef = 0;
*(uint8_t*)0x200001f0 = 0;
*(uint8_t*)0x200001f1 = 0;
*(uint8_t*)0x200001f2 = 0;
*(uint8_t*)0x200001f3 = 0;
*(uint8_t*)0x200001f4 = 0;
*(uint8_t*)0x200001f5 = 0;
*(uint8_t*)0x200001f6 = 0;
*(uint8_t*)0x200001f7 = 0;
*(uint8_t*)0x200001f8 = 0;
*(uint8_t*)0x200001f9 = 0;
*(uint8_t*)0x200001fa = 0;
*(uint8_t*)0x200001fb = 0;
*(uint8_t*)0x200001fc = 0;
*(uint8_t*)0x200001fd = 0;
*(uint8_t*)0x200001fe = 0;
*(uint8_t*)0x200001ff = 0;
syz_io_uring_submit(r[1], r[2], 0x200001c0, 0);
syscall(__NR_io_uring_enter, r[0], 1, 1, 1ul, 0ul, 0ul);
return 0;
}

Next message: Vincenzo Frascino: "Re: [PATCH v2 24/37] arm64: mte: Add in-kernel tag fault handler"
Previous message: Vineeth Pillai: "Re: [RFC PATCH v7 11/23] sched/fair: core wide cfs task priority comparison"
Next in thread: Eric Biggers: "Re: memory leak in getname_flags ( 5.9.0-rc5)"
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