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authorKees Cook <keescook@chromium.org>2023-02-15 14:41:14 -0800
committerJohannes Berg <johannes.berg@intel.com>2023-02-16 09:33:25 +0100
commit1a30a6b25f263686dbf2028d56041ac012b10dcb (patch)
treed2542e74dc9636b0a55886828a5e3286e025dda5
parent3caf31e7b18a90b74a2709d761a0dfa423f2c2e4 (diff)
downloadwpan-next-1a30a6b25f263686dbf2028d56041ac012b10dcb.tar.gz
wifi: brcmfmac: p2p: Introduce generic flexible array frame member
Silence run-time memcpy() false positive warning when processing management frames: memcpy: detected field-spanning write (size 27) of single field "&mgmt_frame->u" at drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c:1469 (size 26) Due to this (soon to be fixed) GCC bug[1], FORTIFY_SOURCE (via __builtin_dynamic_object_size) doesn't recognize that the union may end with a flexible array, and returns "26" (the fixed size of the union), rather than the remaining size of the allocation. Add an explicit flexible array member and set it as the destination here, so that we get the correct coverage for the memcpy(). [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101832 Reported-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arend van Spriel <aspriel@gmail.com> Cc: Franky Lin <franky.lin@broadcom.com> Cc: Hante Meuleman <hante.meuleman@broadcom.com> Cc: Kalle Valo <kvalo@kernel.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Colin Ian King <colin.i.king@gmail.com> Cc: Brian Henriquez <brian.henriquez@cypress.com> Cc: linux-wireless@vger.kernel.org Cc: brcm80211-dev-list.pdl@broadcom.com Cc: SHA-cyfmac-dev-list@infineon.com Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230215224110.never.022-kees@kernel.org [rename 'frame' to 'body'] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
-rw-r--r--drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c4
-rw-r--r--include/linux/ieee80211.h1
2 files changed, 3 insertions, 2 deletions
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
index e975d10e600944..d4492d02e4ea12 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
@@ -1466,8 +1466,8 @@ int brcmf_p2p_notify_action_frame_rx(struct brcmf_if *ifp,
ETH_ALEN);
memcpy(mgmt_frame->sa, e->addr, ETH_ALEN);
mgmt_frame->frame_control = cpu_to_le16(IEEE80211_STYPE_ACTION);
- memcpy(&mgmt_frame->u, frame, mgmt_frame_len);
- mgmt_frame_len += offsetof(struct ieee80211_mgmt, u);
+ memcpy(mgmt_frame->u.body, frame, mgmt_frame_len);
+ mgmt_frame_len += offsetof(struct ieee80211_mgmt, u.body);
freq = ieee80211_channel_to_frequency(ch.control_ch_num,
ch.band == BRCMU_CHAN_BAND_2G ?
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 80d6308dea06f2..2463bdd2a382d8 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -1356,6 +1356,7 @@ struct ieee80211_mgmt {
} __packed wnm_timing_msr;
} u;
} __packed action;
+ DECLARE_FLEX_ARRAY(u8, body); /* Generic frame body */
} u;
} __packed __aligned(2);