From: Peter Seiderer ps.report@gmx.net
[ Upstream commit 425e64440ad0a2f03bdaf04be0ae53dededbaa77 ]
Honour the user given buffer size for the strn_len() calls (otherwise strn_len() will access memory outside of the user given buffer).
Signed-off-by: Peter Seiderer ps.report@gmx.net Reviewed-by: Simon Horman horms@kernel.org Link: https://patch.msgid.link/20250219084527.20488-8-ps.report@gmx.net Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/pktgen.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/net/core/pktgen.c b/net/core/pktgen.c index 1decd6300f34c..6afea369ca213 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -1877,8 +1877,8 @@ static ssize_t pktgen_thread_write(struct file *file, i = len;
/* Read variable name */ - - len = strn_len(&user_buffer[i], sizeof(name) - 1); + max = min(sizeof(name) - 1, count - i); + len = strn_len(&user_buffer[i], max); if (len < 0) return len;
@@ -1908,7 +1908,8 @@ static ssize_t pktgen_thread_write(struct file *file, if (!strcmp(name, "add_device")) { char f[32]; memset(f, 0, 32); - len = strn_len(&user_buffer[i], sizeof(f) - 1); + max = min(sizeof(f) - 1, count - i); + len = strn_len(&user_buffer[i], max); if (len < 0) { ret = len; goto out;