diff options
| author | Shitalkumar Gandhi <shital.gandhi45@gmail.com> | 2026-05-20 16:27:50 +0530 |
|---|---|---|
| committer | Stefan Schmidt <stefan@datenfreihafen.org> | 2026-06-19 22:33:04 +0200 |
| commit | 6d7f7bcf225b2d566176bf6229dbd1252940cb3c (patch) | |
| tree | 3dfb476e2d19e234b7a6a366f32316f9bee44a01 | |
| parent | e09390e439bd7cca30dd10893b1f64802961667a (diff) | |
ieee802154: ca8210: fix pointer truncation in kfifo on 64-bit
ca8210_test_int_driver_write() and ca8210_test_int_user_read() exchange
a kmalloc'd buffer pointer through a struct kfifo, but pass a literal
'4' as the byte count to kfifo_in()/kfifo_out().
This is correct on 32-bit (pointer = 4 bytes), but on 64-bit only the
low 4 bytes of the 8-byte pointer are written into the FIFO. The reader
then reads back 4 bytes into an 8-byte local pointer variable, leaving
the upper 4 bytes uninitialized stack data. The first dereference of
the reconstructed pointer (fifo_buffer[1]) accesses an arbitrary kernel
address and generally results in an oops.
Use sizeof(fifo_buffer) so the byte count matches pointer width on every
architecture.
The driver has no architecture restriction in Kconfig, so any 64-bit
build with CONFIG_IEEE802154_CA8210_DEBUGFS=y is exposed. Issue has
been latent since the driver was added in 2017 because it is most
commonly deployed on 32-bit MCUs.
Found via a custom Coccinelle semantic patch hunting for short-byte
kfifo I/O on byte-mode kfifos used to shuttle pointers.
Fixes: ded845a781a5 ("ieee802154: Add CA8210 IEEE 802.15.4 device driver")
Cc: stable@vger.kernel.org
Signed-off-by: Shitalkumar Gandhi <shitalkumar.gandhi@cambiumnetworks.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/20260520105750.30144-1-shitalkumar.gandhi@cambiumnetworks.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
| -rw-r--r-- | drivers/net/ieee802154/ca8210.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/ieee802154/ca8210.c b/drivers/net/ieee802154/ca8210.c index bf837adfebb2..01af4f9cf7f2 100644 --- a/drivers/net/ieee802154/ca8210.c +++ b/drivers/net/ieee802154/ca8210.c @@ -595,7 +595,7 @@ static int ca8210_test_int_driver_write( fifo_buffer = kmemdup(buf, len, GFP_KERNEL); if (!fifo_buffer) return -ENOMEM; - kfifo_in(&test->up_fifo, &fifo_buffer, 4); + kfifo_in(&test->up_fifo, &fifo_buffer, sizeof(fifo_buffer)); wake_up_interruptible(&priv->test.readq); return 0; @@ -2526,6 +2526,7 @@ static ssize_t ca8210_test_int_user_read( struct ca8210_priv *priv = filp->private_data; unsigned char *fifo_buffer; unsigned long bytes_not_copied; + unsigned int copied; if (filp->f_flags & O_NONBLOCK) { /* Non-blocking mode */ @@ -2539,7 +2540,8 @@ static ssize_t ca8210_test_int_user_read( ); } - if (kfifo_out(&priv->test.up_fifo, &fifo_buffer, 4) != 4) { + copied = kfifo_out(&priv->test.up_fifo, &fifo_buffer, sizeof(fifo_buffer)); + if (copied != sizeof(fifo_buffer)) { dev_err( &priv->spi->dev, "test_interface: Wrong number of elements popped from upstream fifo\n" |