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authorLinus Torvalds <torvalds@linux-foundation.org>2016-04-28 19:54:50 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-04-28 19:54:50 -0700
commit8f3603a210970d665e7cecf6623331ce6b24f713 (patch)
tree3dc33db5d8ea1c8a741a91d0e05c38629753352e /drivers/firmware
parentba14e961b4fc0b0efcb1b2af7aab605bfce55fb8 (diff)
parentede85e90be26e5de2a72f76feec01cfc5281d4bd (diff)
Merge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI fix from Ingo Molnar: "This fixes a bug in the efivars code" * 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi: Fix out-of-bounds read in variable_matches()
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/efi/vars.c37
1 files changed, 26 insertions, 11 deletions
diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index 0ac594c0a234..34b741940494 100644
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -202,29 +202,44 @@ static const struct variable_validate variable_validate[] = {
{ NULL_GUID, "", NULL },
};
+/*
+ * Check if @var_name matches the pattern given in @match_name.
+ *
+ * @var_name: an array of @len non-NUL characters.
+ * @match_name: a NUL-terminated pattern string, optionally ending in "*". A
+ * final "*" character matches any trailing characters @var_name,
+ * including the case when there are none left in @var_name.
+ * @match: on output, the number of non-wildcard characters in @match_name
+ * that @var_name matches, regardless of the return value.
+ * @return: whether @var_name fully matches @match_name.
+ */
static bool
variable_matches(const char *var_name, size_t len, const char *match_name,
int *match)
{
for (*match = 0; ; (*match)++) {
char c = match_name[*match];
- char u = var_name[*match];
- /* Wildcard in the matching name means we've matched */
- if (c == '*')
+ switch (c) {
+ case '*':
+ /* Wildcard in @match_name means we've matched. */
return true;
- /* Case sensitive match */
- if (!c && *match == len)
- return true;
+ case '\0':
+ /* @match_name has ended. Has @var_name too? */
+ return (*match == len);
- if (c != u)
+ default:
+ /*
+ * We've reached a non-wildcard char in @match_name.
+ * Continue only if there's an identical character in
+ * @var_name.
+ */
+ if (*match < len && c == var_name[*match])
+ continue;
return false;
-
- if (!c)
- return true;
+ }
}
- return true;
}
bool