From 9bbb3b60905039f76aea8c2d4a515cf819bcebeb Mon Sep 17 00:00:00 2001 From: Tom Rix Date: Sun, 4 Oct 2020 06:19:31 -0700 Subject: [PATCH] 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 Reviewed-by: Brian Norris Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20201004131931.29782-1-trix@redhat.com Signed-off-by: Sasha Levin --- drivers/net/wireless/marvell/mwifiex/sdio.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/wireless/marvell/mwifiex/sdio.c b/drivers/net/wireless/marvell/mwifiex/sdio.c index a042965962a2d..1b6bee5465288 100644 --- a/drivers/net/wireless/marvell/mwifiex/sdio.c +++ b/drivers/net/wireless/marvell/mwifiex/sdio.c @@ -1976,6 +1976,8 @@ 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;