diff options
| author | Dan Carpenter <dan.carpenter@oracle.com> | 2019-04-24 12:52:18 +0300 |
|---|---|---|
| committer | Kalle Valo <kvalo@codeaurora.org> | 2019-05-01 18:25:09 +0300 |
| commit | e025da3d7aa4770bb1d1b3b0aa7cc4da1744852d (patch) | |
| tree | 9764823eeb0903fb2043a560d2ba6b45897d6c72 /drivers/net/wireless | |
| parent | e3037485c68ec1a299ff41160d8fedbd4abc29b9 (diff) | |
brcm80211: potential NULL dereference in brcmf_cfg80211_vndr_cmds_dcmd_handler()
If "ret_len" is negative then it could lead to a NULL dereference.
The "ret_len" value comes from nl80211_vendor_cmd(), if it's negative
then we don't allocate the "dcmd_buf" buffer. Then we pass "ret_len" to
brcmf_fil_cmd_data_set() where it is cast to a very high u32 value.
Most of the functions in that call tree check whether the buffer we pass
is NULL but there are at least a couple places which don't such as
brcmf_dbg_hex_dump() and brcmf_msgbuf_query_dcmd(). We memcpy() to and
from the buffer so it would result in a NULL dereference.
The fix is to change the types so that "ret_len" can't be negative. (If
we memcpy() zero bytes to NULL, that's a no-op and doesn't cause an
issue).
Fixes: 1bacb0487d0e ("brcmfmac: replace cfg80211 testmode with vendor command")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Diffstat (limited to 'drivers/net/wireless')
| -rw-r--r-- | drivers/net/wireless/broadcom/brcm80211/brcmfmac/vendor.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/vendor.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/vendor.c index 8eff2753abad..d493021f6031 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/vendor.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/vendor.c @@ -35,9 +35,10 @@ static int brcmf_cfg80211_vndr_cmds_dcmd_handler(struct wiphy *wiphy, struct brcmf_if *ifp; const struct brcmf_vndr_dcmd_hdr *cmdhdr = data; struct sk_buff *reply; - int ret, payload, ret_len; + unsigned int payload, ret_len; void *dcmd_buf = NULL, *wr_pointer; u16 msglen, maxmsglen = PAGE_SIZE - 0x100; + int ret; if (len < sizeof(*cmdhdr)) { brcmf_err("vendor command too short: %d\n", len); @@ -65,7 +66,7 @@ static int brcmf_cfg80211_vndr_cmds_dcmd_handler(struct wiphy *wiphy, brcmf_err("oversize return buffer %d\n", ret_len); ret_len = BRCMF_DCMD_MAXLEN; } - payload = max(ret_len, len) + 1; + payload = max_t(unsigned int, ret_len, len) + 1; dcmd_buf = vzalloc(payload); if (NULL == dcmd_buf) return -ENOMEM; |