coredump: validate that path doesn't exceed UNIX_PATH_MAX

so we don't pointlessly accepts things that go over the limit.

Link: https://lore.kernel.org/20250612-work-coredump-massage-v1-4-315c0c34ba94@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/coredump.c b/fs/coredump.c
index 70e37435eca956f338fd0ed3f6d60da18f0d3b73..a64b87878ab37e917132e536fddd1a608f51340f 100644 (file)
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -1388,6 +1388,8 @@ void validate_coredump_safety(void)
 
 static inline bool check_coredump_socket(void)
 {
+       const char *p;
+
        if (core_pattern[0] != '@')
                return true;
 
@@ -1407,10 +1409,15 @@ static inline bool check_coredump_socket(void)
                /* ... and if so must be an absolute path. */
                if (core_pattern[2] != '/')
                        return false;
-               /* Anything else is unsupported. */
-               return false;
+               p = &core_pattern[2];
+       } else {
+               p = &core_pattern[1];
        }
 
+       /* The path obviously cannot exceed UNIX_PATH_MAX. */
+       if (strlen(p) >= UNIX_PATH_MAX)
+               return false;
+
        return true;
 }