This is a note to let you know that I've just added the patch titled
mwifiex: fix double free
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mwifiex-fix-double-free.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a82c761ef59e2d5199c23d91eef99fd6e2e2b147
Author: Tom Rix <trix@xxxxxxxxxx>
Date: Sun Oct 4 06:19:31 2020 -0700
mwifiex: fix double free
[ Upstream commit 53708f4fd9cfe389beab5c8daa763bcd0e0b4aef ]
clang static analysis reports this problem:
sdio.c:2403:3: warning: Attempt to free released memory
kfree(card->mpa_rx.buf);
^~~~~~~~~~~~~~~~~~~~~~~
When mwifiex_init_sdio() fails in its first call to
mwifiex_alloc_sdio_mpa_buffer, it falls back to calling it
again. If the second alloc of mpa_tx.buf fails, the error
handler will try to free the old, previously freed mpa_rx.buf.
Reviewing the code, it looks like a second double free would
happen with mwifiex_cleanup_sdio().
So set both pointers to NULL when they are freed.
Fixes: 5e6e3a92b9a4 ("wireless: mwifiex: initial commit for Marvell mwifiex driver")
Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20201004131931.29782-1-trix@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/wireless/marvell/mwifiex/sdio.c b/drivers/net/wireless/marvell/mwifiex/sdio.c
index bfbe3aa058d93..0773d81072aa1 100644
--- a/drivers/net/wireless/marvell/mwifiex/sdio.c
+++ b/drivers/net/wireless/marvell/mwifiex/sdio.c
@@ -1985,6 +1985,8 @@ static int mwifiex_alloc_sdio_mpa_buffers(struct mwifiex_adapter *adapter,
kfree(card->mpa_rx.buf);
card->mpa_tx.buf_size = 0;
card->mpa_rx.buf_size = 0;
+ card->mpa_tx.buf = NULL;
+ card->mpa_rx.buf = NULL;
}
return ret;
