6.1-stable review patch. If anyone has any objections, please let me know.
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From: Junrui Luo moonafterrain@outlook.com
commit 324f3e03e8a85931ce0880654e3c3eb38b0f0bba upstream.
The function detect_stream_formats() reads the stream_count value directly from a FireWire device without validating it. This can lead to out-of-bounds writes when a malicious device provides a stream_count value greater than MAX_STREAMS.
Fix by applying the same validation to both TX and RX stream counts in detect_stream_formats().
Reported-by: Yuhao Jiang danisjiang@gmail.com Reported-by: Junrui Luo moonafterrain@outlook.com Fixes: 58579c056c1c ("ALSA: dice: use extended protocol to detect available stream formats") Cc: stable@vger.kernel.org Reviewed-by: Takashi Sakamoto o-takashi@sakamocchi.jp Signed-off-by: Junrui Luo moonafterrain@outlook.com Link: https://patch.msgid.link/SYBPR01MB7881B043FC68B4C0DA40B73DAFDCA@SYBPR01MB788... Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- sound/firewire/dice/dice-extension.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/sound/firewire/dice/dice-extension.c +++ b/sound/firewire/dice/dice-extension.c @@ -116,7 +116,7 @@ static int detect_stream_formats(struct break;
base_offset += EXT_APP_STREAM_ENTRIES; - stream_count = be32_to_cpu(reg[0]); + stream_count = min_t(unsigned int, be32_to_cpu(reg[0]), MAX_STREAMS); err = read_stream_entries(dice, section_addr, base_offset, stream_count, mode, dice->tx_pcm_chs, @@ -125,7 +125,7 @@ static int detect_stream_formats(struct break;
base_offset += stream_count * EXT_APP_STREAM_ENTRY_SIZE; - stream_count = be32_to_cpu(reg[1]); + stream_count = min_t(unsigned int, be32_to_cpu(reg[1]), MAX_STREAMS); err = read_stream_entries(dice, section_addr, base_offset, stream_count, mode, dice->rx_pcm_chs,