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Revision f2d7b53c0153f2daa8bc8f1ff29b5a1e03a36458 authored by Alexander Potapenko on 02 November 2022, 10:15:00 UTC, committed by Alexander Potapenko on 02 November 2022, 10:55:06 UTC 
x86/traps: avoid KMSAN bugs originating from handle_bug()
 
There is a case in exc_invalid_op handler that is executed outside the
irqentry_enter()/irqentry_exit() region when an UD2 instruction is used
to encode a call to __warn().

In that case the `struct pt_regs` passed to the interrupt handler is
never unpoisoned by KMSAN (this is normally done in irqentry_enter()),
which leads to false positives inside handle_bug().

Use kmsan_unpoison_entry_regs() to explicitly unpoison those registers
before using them.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Signed-off-by: Alexander Potapenko <glider@google.com>
1 parent 4dbc4d5
Raw File
net_utils.c 
// SPDX-License-Identifier: GPL-2.0
#include <linux/string.h>
#include <linux/if_ether.h>
#include <linux/ctype.h>
#include <linux/kernel.h>

bool mac_pton(const char *s, u8 *mac)
{
	int i;

	/* XX:XX:XX:XX:XX:XX */
	if (strlen(s) < 3 * ETH_ALEN - 1)
		return false;

	/* Don't dirty result unless string is valid MAC. */
	for (i = 0; i < ETH_ALEN; i++) {
		if (!isxdigit(s[i * 3]) || !isxdigit(s[i * 3 + 1]))
			return false;
		if (i != ETH_ALEN - 1 && s[i * 3 + 2] != ':')
			return false;
	}
	for (i = 0; i < ETH_ALEN; i++) {
		mac[i] = (hex_to_bin(s[i * 3]) << 4) | hex_to_bin(s[i * 3 + 1]);
	}
	return true;
}
EXPORT_SYMBOL(mac_pton);
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