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| author | Arnd Bergmann <arnd@arndb.de> | 2021-10-20 11:59:07 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-18 21:17:20 +0300 |
| commit | 6f11f2096b2c752aea7e5c72d602626e893867ef (patch) | |
| tree | 0fddac4a29ead3e9338fe35c2681e9a902984919 /drivers/net/wireless/ath | |
| parent | 9ebaafec97fb6c0c816f0f355976aaa0811008d4 (diff) | |
| download | linux-6f11f2096b2c752aea7e5c72d602626e893867ef.tar.xz | |
ath10k: fix invalid dma_addr_t token assignment
commit 937e79c67740d1d84736730d679f3cb2552f990e upstream.
Using a kernel pointer in place of a dma_addr_t token can
lead to undefined behavior if that makes it into cache
management functions. The compiler caught one such attempt
in a cast:
drivers/net/wireless/ath/ath10k/mac.c: In function 'ath10k_add_interface':
drivers/net/wireless/ath/ath10k/mac.c:5586:47: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
5586 | arvif->beacon_paddr = (dma_addr_t)arvif->beacon_buf;
| ^
Looking through how this gets used down the way, I'm fairly
sure that beacon_paddr is never accessed again for ATH10K_DEV_TYPE_HL
devices, and if it was accessed, that would be a bug.
Change the assignment to use a known-invalid address token
instead, which avoids the warning and makes it easier to catch
bugs if it does end up getting used.
Fixes: e263bdab9c0e ("ath10k: high latency fixes for beacon buffer")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20211014075153.3655910-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net/wireless/ath')
| -rw-r--r-- | drivers/net/wireless/ath/ath10k/mac.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c index 5ec19d91cf37..1f73fbfee0c0 100644 --- a/drivers/net/wireless/ath/ath10k/mac.c +++ b/drivers/net/wireless/ath/ath10k/mac.c @@ -5583,7 +5583,15 @@ static int ath10k_add_interface(struct ieee80211_hw *hw, if (ar->bus_param.dev_type == ATH10K_DEV_TYPE_HL) { arvif->beacon_buf = kmalloc(IEEE80211_MAX_FRAME_LEN, GFP_KERNEL); - arvif->beacon_paddr = (dma_addr_t)arvif->beacon_buf; + + /* Using a kernel pointer in place of a dma_addr_t + * token can lead to undefined behavior if that + * makes it into cache management functions. Use a + * known-invalid address token instead, which + * avoids the warning and makes it easier to catch + * bugs if it does end up getting used. + */ + arvif->beacon_paddr = DMA_MAPPING_ERROR; } else { arvif->beacon_buf = dma_alloc_coherent(ar->dev, |