6.1-stable review patch. If anyone has any objections, please let me know.
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From: Ekansh Gupta quic_ekangupt@quicinc.com
commit e966eae72762ecfdbdb82627e2cda48845b9dd66 upstream.
For non-registered buffer, fastrpc driver copies the buffer and pass it to the remote subsystem. There is a problem with current implementation of page size calculation which is not considering the offset in the calculation. This might lead to passing of improper and out-of-bounds page size which could result in memory issue. Calculate page start and page end using the offset adjusted address instead of absolute address.
Fixes: 02b45b47fbe8 ("misc: fastrpc: fix remote page size calculation") Cc: stable@kernel.org Signed-off-by: Ekansh Gupta quic_ekangupt@quicinc.com Signed-off-by: Srinivas Kandagatla srinivas.kandagatla@linaro.org Link: https://lore.kernel.org/r/20250110134239.123603-4-srinivas.kandagatla@linaro... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/misc/fastrpc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/misc/fastrpc.c +++ b/drivers/misc/fastrpc.c @@ -961,8 +961,8 @@ static int fastrpc_get_args(u32 kernel, (pkt_size - rlen); pages[i].addr = pages[i].addr & PAGE_MASK;
- pg_start = (args & PAGE_MASK) >> PAGE_SHIFT; - pg_end = ((args + len - 1) & PAGE_MASK) >> PAGE_SHIFT; + pg_start = (rpra[i].buf.pv & PAGE_MASK) >> PAGE_SHIFT; + pg_end = ((rpra[i].buf.pv + len - 1) & PAGE_MASK) >> PAGE_SHIFT; pages[i].size = (pg_end - pg_start + 1) * PAGE_SIZE; args = args + mlen; rlen -= mlen;