From: Ekansh Gupta <quic_ekangupt@xxxxxxxxxxx>
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@xxxxxxxxxx
Signed-off-by: Ekansh Gupta <quic_ekangupt@xxxxxxxxxxx>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20250110134239.123603-4-srinivas.kandagatla@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/misc/fastrpc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -1019,8 +1019,8 @@ 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;
Patches currently in stable-queue which might be from quic_ekangupt@xxxxxxxxxxx are
queue-6.13/misc-fastrpc-fix-registered-buffer-page-address.patch
queue-6.13/misc-fastrpc-fix-copy-buffer-page-size.patch
