From: Dmitry Antipov dmantipov@yandex.ru
[ Upstream commit cbaccdc42483c65016f1bae89128c08dc17cfb2a ]
When compiling with clang 16.0.6 and CONFIG_FORTIFY_SOURCE=y, I've noticed the following (somewhat confusing due to absence of an actual source code location):
In file included from drivers/net/wireless/virtual/mac80211_hwsim.c:18: In file included from ./include/linux/slab.h:16: In file included from ./include/linux/gfp.h:7: In file included from ./include/linux/mmzone.h:8: In file included from ./include/linux/spinlock.h:56: In file included from ./include/linux/preempt.h:79: In file included from ./arch/x86/include/asm/preempt.h:9: In file included from ./include/linux/thread_info.h:60: In file included from ./arch/x86/include/asm/thread_info.h:53: In file included from ./arch/x86/include/asm/cpufeature.h:5: In file included from ./arch/x86/include/asm/processor.h:23: In file included from ./arch/x86/include/asm/msr.h:11: In file included from ./arch/x86/include/asm/cpumask.h:5: In file included from ./include/linux/cpumask.h:12: In file included from ./include/linux/bitmap.h:11: In file included from ./include/linux/string.h:254: ./include/linux/fortify-string.h:592:4: warning: call to '__read_overflow2_field' declared with 'warning' attribute: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Wattribute-warning] __read_overflow2_field(q_size_field, size);
The compiler actually complains on 'mac80211_hwsim_get_et_strings()' where fortification logic inteprets call to 'memcpy()' as an attempt to copy the whole 'mac80211_hwsim_gstrings_stats' array from its first member and so issues an overread warning. This warning may be silenced by passing an address of the whole array and not the first member to 'memcpy()'.
Signed-off-by: Dmitry Antipov dmantipov@yandex.ru Link: https://lore.kernel.org/r/20230829094140.234636-1-dmantipov@yandex.ru Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/mac80211_hwsim.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 0d41f172a1dc2..037358606a51a 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -2543,7 +2543,7 @@ static void mac80211_hwsim_get_et_strings(struct ieee80211_hw *hw, u32 sset, u8 *data) { if (sset == ETH_SS_STATS) - memcpy(data, *mac80211_hwsim_gstrings_stats, + memcpy(data, mac80211_hwsim_gstrings_stats, sizeof(mac80211_hwsim_gstrings_stats)); }