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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2025-11-20 09:34:49 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-01-11 15:21:50 +0100 |
| commit | 3dd6d01384823e1bd8602873153d6fc4337ac4fe (patch) | |
| tree | 3c9b6c3ef03c4a72ecc1e3a9a20841dd5a03691c /drivers/spi | |
| parent | a287987af35425787f1843eba24638b71aea2b49 (diff) | |
| download | linux-3dd6d01384823e1bd8602873153d6fc4337ac4fe.tar.gz linux-3dd6d01384823e1bd8602873153d6fc4337ac4fe.tar.bz2 linux-3dd6d01384823e1bd8602873153d6fc4337ac4fe.zip | |
spi: fsl-cpm: Check length parity before switching to 16 bit mode
commit 1417927df8049a0194933861e9b098669a95c762 upstream.
Commit fc96ec826bce ("spi: fsl-cpm: Use 16 bit mode for large transfers
with even size") failed to make sure that the size is really even
before switching to 16 bit mode. Until recently the problem went
unnoticed because kernfs uses a pre-allocated bounce buffer of size
PAGE_SIZE for reading EEPROM.
But commit 8ad6249c51d0 ("eeprom: at25: convert to spi-mem API")
introduced an additional dynamically allocated bounce buffer whose size
is exactly the size of the transfer, leading to a buffer overrun in
the fsl-cpm driver when that size is odd.
Add the missing length parity verification and remain in 8 bit mode
when the length is not even.
Fixes: fc96ec826bce ("spi: fsl-cpm: Use 16 bit mode for large transfers with even size")
Cc: stable@vger.kernel.org
Closes: https://lore.kernel.org/all/638496dd-ec60-4e53-bad7-eb657f67d580@csgroup.eu/
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Sverdlin Alexander <alexander.sverdlin@siemens.com>
Link: https://patch.msgid.link/3c4d81c3923c93f95ec56702a454744a4bad3cfc.1763627618.git.christophe.leroy@csgroup.eu
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-fsl-spi.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c index 97faf984801f..750e2cd2594d 100644 --- a/drivers/spi/spi-fsl-spi.c +++ b/drivers/spi/spi-fsl-spi.c @@ -336,7 +336,7 @@ static int fsl_spi_prepare_message(struct spi_controller *ctlr, if (t->bits_per_word == 16 || t->bits_per_word == 32) t->bits_per_word = 8; /* pretend its 8 bits */ if (t->bits_per_word == 8 && t->len >= 256 && - (mpc8xxx_spi->flags & SPI_CPM1)) + !(t->len & 1) && (mpc8xxx_spi->flags & SPI_CPM1)) t->bits_per_word = 16; } } |