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| author | Johannes Berg <johannes.berg@intel.com> | 2011-11-04 11:01:46 +0100 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2011-11-07 13:19:14 -0500 |
| commit | 3b6ef6334febb05d3050a96546e635f038dbcb15 (patch) | |
| tree | 30f568f999c0ffd3a3011f0f495e759b7f19c2f7 /net | |
| parent | 133a3ff2c934223a8143bfa52401bba962a97165 (diff) | |
| download | linux-3b6ef6334febb05d3050a96546e635f038dbcb15.tar.gz linux-3b6ef6334febb05d3050a96546e635f038dbcb15.tar.bz2 linux-3b6ef6334febb05d3050a96546e635f038dbcb15.zip | |
cfg80211: fix cmp_ies
When comparing two items by IE, the sort order
wasn't stable, which could lead to issues in the
rbtree. Make it stable by making a missing IE
sort before a present IE.
Also sort by length first if it differs and then
by contents.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/wireless/scan.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 0fb142410404..dc23b31594e0 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -259,17 +259,20 @@ static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2) { const u8 *ie1 = cfg80211_find_ie(num, ies1, len1); const u8 *ie2 = cfg80211_find_ie(num, ies2, len2); - int r; + /* equal if both missing */ if (!ie1 && !ie2) return 0; - if (!ie1 || !ie2) + /* sort missing IE before (left of) present IE */ + if (!ie1) return -1; + if (!ie2) + return 1; - r = memcmp(ie1 + 2, ie2 + 2, min(ie1[1], ie2[1])); - if (r == 0 && ie1[1] != ie2[1]) + /* sort by length first, then by contents */ + if (ie1[1] != ie2[1]) return ie2[1] - ie1[1]; - return r; + return memcmp(ie1 + 2, ie2 + 2, ie1[1]); } static bool is_bss(struct cfg80211_bss *a, |