Revision 34f5b0066435ffb793049b84fafd29fa195bcf90 authored by Sasha Levin on 16 September 2015, 19:30:21 UTC, committed by David S. Miller on 18 September 2015, 05:13:32 UTC
If we didn't call ATMARP_MKIP before ATMARP_ENCAP the VCC descriptor is
non-existant and we'll end up dereferencing a NULL ptr:

[1033173.491930] kasan: GPF could be caused by NULL-ptr deref or user memory accessirq event stamp: 123386
[1033173.493678] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN
[1033173.493689] Modules linked in:
[1033173.493697] CPU: 9 PID: 23815 Comm: trinity-c64 Not tainted 4.2.0-next-20150911-sasha-00043-g353d875-dirty #2545
[1033173.493706] task: ffff8800630c4000 ti: ffff880063110000 task.ti: ffff880063110000
[1033173.493823] RIP: clip_ioctl (net/atm/clip.c:320 net/atm/clip.c:689)
[1033173.493826] RSP: 0018:ffff880063117a88  EFLAGS: 00010203
[1033173.493828] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 000000000000000c
[1033173.493830] RDX: 0000000000000002 RSI: ffffffffb3f10720 RDI: 0000000000000014
[1033173.493832] RBP: ffff880063117b80 R08: ffff88047574d9a4 R09: 0000000000000000
[1033173.493834] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1000c622f53
[1033173.493836] R13: ffff8800cb905500 R14: ffff8808d6da2000 R15: 00000000fffffdfd
[1033173.493840] FS:  00007fa56b92d700(0000) GS:ffff880478000000(0000) knlGS:0000000000000000
[1033173.493843] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[1033173.493845] CR2: 0000000000000000 CR3: 00000000630e8000 CR4: 00000000000006a0
[1033173.493855] Stack:
[1033173.493862]  ffffffffb0b60444 000000000000eaea 0000000041b58ab3 ffffffffb3c3ce32
[1033173.493867]  ffffffffb0b6f3e0 ffffffffb0b60444 ffffffffb5ea2e50 1ffff1000c622f5e
[1033173.493873]  ffff8800630c4cd8 00000000000ee09a ffffffffb3ec4888 ffffffffb5ea2de8
[1033173.493874] Call Trace:
[1033173.494108] do_vcc_ioctl (net/atm/ioctl.c:170)
[1033173.494113] vcc_ioctl (net/atm/ioctl.c:189)
[1033173.494116] svc_ioctl (net/atm/svc.c:605)
[1033173.494200] sock_do_ioctl (net/socket.c:874)
[1033173.494204] sock_ioctl (net/socket.c:958)
[1033173.494244] do_vfs_ioctl (fs/ioctl.c:43 fs/ioctl.c:607)
[1033173.494290] SyS_ioctl (fs/ioctl.c:622 fs/ioctl.c:613)
[1033173.494295] entry_SYSCALL_64_fastpath (arch/x86/entry/entry_64.S:186)
[1033173.494362] Code: fa 48 c1 ea 03 80 3c 02 00 0f 85 50 09 00 00 49 8b 9e 60 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 14 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 14 09 00
All code

========
   0:   fa                      cli
   1:   48 c1 ea 03             shr    $0x3,%rdx
   5:   80 3c 02 00             cmpb   $0x0,(%rdx,%rax,1)
   9:   0f 85 50 09 00 00       jne    0x95f
   f:   49 8b 9e 60 06 00 00    mov    0x660(%r14),%rbx
  16:   48 b8 00 00 00 00 00    movabs $0xdffffc0000000000,%rax
  1d:   fc ff df
  20:   48 8d 7b 14             lea    0x14(%rbx),%rdi
  24:   48 89 fa                mov    %rdi,%rdx
  27:   48 c1 ea 03             shr    $0x3,%rdx
  2b:*  0f b6 04 02             movzbl (%rdx,%rax,1),%eax               <-- trapping instruction
  2f:   48 89 fa                mov    %rdi,%rdx
  32:   83 e2 07                and    $0x7,%edx
  35:   38 d0                   cmp    %dl,%al
  37:   7f 08                   jg     0x41
  39:   84 c0                   test   %al,%al
  3b:   0f 85 14 09 00 00       jne    0x955

Code starting with the faulting instruction
===========================================
   0:   0f b6 04 02             movzbl (%rdx,%rax,1),%eax
   4:   48 89 fa                mov    %rdi,%rdx
   7:   83 e2 07                and    $0x7,%edx
   a:   38 d0                   cmp    %dl,%al
   c:   7f 08                   jg     0x16
   e:   84 c0                   test   %al,%al
  10:   0f 85 14 09 00 00       jne    0x92a
[1033173.494366] RIP clip_ioctl (net/atm/clip.c:320 net/atm/clip.c:689)
[1033173.494368]  RSP <ffff880063117a88>

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 1d325d2
Raw File
memtest.c
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/memblock.h>

static u64 patterns[] __initdata = {
	/* The first entry has to be 0 to leave memtest with zeroed memory */
	0,
	0xffffffffffffffffULL,
	0x5555555555555555ULL,
	0xaaaaaaaaaaaaaaaaULL,
	0x1111111111111111ULL,
	0x2222222222222222ULL,
	0x4444444444444444ULL,
	0x8888888888888888ULL,
	0x3333333333333333ULL,
	0x6666666666666666ULL,
	0x9999999999999999ULL,
	0xccccccccccccccccULL,
	0x7777777777777777ULL,
	0xbbbbbbbbbbbbbbbbULL,
	0xddddddddddddddddULL,
	0xeeeeeeeeeeeeeeeeULL,
	0x7a6c7258554e494cULL, /* yeah ;-) */
};

static void __init reserve_bad_mem(u64 pattern, phys_addr_t start_bad, phys_addr_t end_bad)
{
	pr_info("  %016llx bad mem addr %pa - %pa reserved\n",
		cpu_to_be64(pattern), &start_bad, &end_bad);
	memblock_reserve(start_bad, end_bad - start_bad);
}

static void __init memtest(u64 pattern, phys_addr_t start_phys, phys_addr_t size)
{
	u64 *p, *start, *end;
	phys_addr_t start_bad, last_bad;
	phys_addr_t start_phys_aligned;
	const size_t incr = sizeof(pattern);

	start_phys_aligned = ALIGN(start_phys, incr);
	start = __va(start_phys_aligned);
	end = start + (size - (start_phys_aligned - start_phys)) / incr;
	start_bad = 0;
	last_bad = 0;

	for (p = start; p < end; p++)
		*p = pattern;

	for (p = start; p < end; p++, start_phys_aligned += incr) {
		if (*p == pattern)
			continue;
		if (start_phys_aligned == last_bad + incr) {
			last_bad += incr;
			continue;
		}
		if (start_bad)
			reserve_bad_mem(pattern, start_bad, last_bad + incr);
		start_bad = last_bad = start_phys_aligned;
	}
	if (start_bad)
		reserve_bad_mem(pattern, start_bad, last_bad + incr);
}

static void __init do_one_pass(u64 pattern, phys_addr_t start, phys_addr_t end)
{
	u64 i;
	phys_addr_t this_start, this_end;

	for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &this_start,
				&this_end, NULL) {
		this_start = clamp(this_start, start, end);
		this_end = clamp(this_end, start, end);
		if (this_start < this_end) {
			pr_info("  %pa - %pa pattern %016llx\n",
				&this_start, &this_end, cpu_to_be64(pattern));
			memtest(pattern, this_start, this_end - this_start);
		}
	}
}

/* default is disabled */
static unsigned int memtest_pattern __initdata;

static int __init parse_memtest(char *arg)
{
	int ret = 0;

	if (arg)
		ret = kstrtouint(arg, 0, &memtest_pattern);
	else
		memtest_pattern = ARRAY_SIZE(patterns);

	return ret;
}

early_param("memtest", parse_memtest);

void __init early_memtest(phys_addr_t start, phys_addr_t end)
{
	unsigned int i;
	unsigned int idx = 0;

	if (!memtest_pattern)
		return;

	pr_info("early_memtest: # of tests: %u\n", memtest_pattern);
	for (i = memtest_pattern-1; i < UINT_MAX; --i) {
		idx = i % ARRAY_SIZE(patterns);
		do_one_pass(patterns[idx], start, end);
	}
}
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