diff mbox series

[net-next,v1,3/5] net: pktgen: fix access outside of user given buffer in pktgen_thread_write()

Message ID 20250117141613.691452-4-ps.report@gmx.net (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series Some pktgen fixes/improvments | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 6 of 6 maintainers
netdev/build_clang success Errors and warnings before: 1 this patch: 1
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 19 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest fail net-next-2025-01-17--18-00 (tests: 889)

Commit Message

Peter Seiderer Jan. 17, 2025, 2:16 p.m. UTC 
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>
---
 net/core/pktgen.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 4f8ec6c9bed4..9536f9c4d9ef 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -1897,8 +1897,8 @@  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;
 
@@ -1928,7 +1928,8 @@  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;