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| author | Len Baker <len.baker@gmx.com> | 2021-09-19 14:40:40 +0300 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2021-09-23 14:38:11 +0300 |
| commit | 40f231e75a1d986a8f8705765e2c5c770370318c (patch) | |
| tree | b66a47a9a11c8d43748634f8091abbef5171c436 /net/wireless | |
| parent | 68ba1131d4b566dfad0b319a861552778a6cdfb8 (diff) | |
| download | linux-40f231e75a1d986a8f8705765e2c5c770370318c.tar.xz | |
nl80211: prefer struct_size over open coded arithmetic
As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.
So, use the struct_size() helper to do the arithmetic instead of the
argument "size + count * size" in the kzalloc() functions.
Also, take the opportunity to refactor the memcpy() call to use the
flex_array_size() helper.
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
Signed-off-by: Len Baker <len.baker@gmx.com>
Link: https://lore.kernel.org/r/20210919114040.41522-1-len.baker@gmx.com
[remove unnecessary variable]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/wireless')
| -rw-r--r-- | net/wireless/nl80211.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index bf7cd4752547..e4787c74e80b 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -11767,8 +11767,9 @@ static int nl80211_set_cqm_rssi(struct genl_info *info, if (n_thresholds) { struct cfg80211_cqm_config *cqm_config; - cqm_config = kzalloc(sizeof(struct cfg80211_cqm_config) + - n_thresholds * sizeof(s32), GFP_KERNEL); + cqm_config = kzalloc(struct_size(cqm_config, rssi_thresholds, + n_thresholds), + GFP_KERNEL); if (!cqm_config) { err = -ENOMEM; goto unlock; @@ -11777,7 +11778,8 @@ static int nl80211_set_cqm_rssi(struct genl_info *info, cqm_config->rssi_hyst = hysteresis; cqm_config->n_rssi_thresholds = n_thresholds; memcpy(cqm_config->rssi_thresholds, thresholds, - n_thresholds * sizeof(s32)); + flex_array_size(cqm_config, rssi_thresholds, + n_thresholds)); wdev->cqm_config = cqm_config; } @@ -15081,9 +15083,7 @@ static int nl80211_set_sar_specs(struct sk_buff *skb, struct genl_info *info) if (specs > rdev->wiphy.sar_capa->num_freq_ranges) return -EINVAL; - sar_spec = kzalloc(sizeof(*sar_spec) + - specs * sizeof(struct cfg80211_sar_sub_specs), - GFP_KERNEL); + sar_spec = kzalloc(struct_size(sar_spec, sub_specs, specs), GFP_KERNEL); if (!sar_spec) return -ENOMEM; |