[PATCH 4.19 099/422] brcmfmac: fix wrong strnchr usage

From: Greg Kroah-Hartman
Date: Tue Nov 19 2019 - 00:29:45 EST


From: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>

[ Upstream commit cb18e2e9ec71d42409a51b83546686c609780dde ]

strnchr takes arguments in the order of its name: string, max bytes to
read, character to search for. Here we're passing '\n' aka 10 as the
buffer size, and searching for sizeof(buf) aka BRCMF_DCMD_SMLEN aka
256 (aka '\0', since it's implicitly converted to char) within those 10
bytes.

Just interchanging the last two arguments would still leave a bug,
because if we've been successful once, there are not sizeof(buf)
characters left after the new value of p.

Since clmver is immediately afterwards passed as a %s argument, I assume
that it is actually a properly nul-terminated string. For that case, we
have strreplace().

Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c
index 27893af63ebc3..8510d207ee87d 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c
@@ -296,9 +296,7 @@ int brcmf_c_preinit_dcmds(struct brcmf_if *ifp)
/* Replace all newline/linefeed characters with space
* character
*/
- ptr = clmver;
- while ((ptr = strnchr(ptr, '\n', sizeof(buf))) != NULL)
- *ptr = ' ';
+ strreplace(clmver, '\n', ' ');

brcmf_dbg(INFO, "CLM version = %s\n", clmver);
}
--
2.20.1