a473514bf6
[ Upstream commit e025da3d7aa4770bb1d1b3b0aa7cc4da1744852d ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.