From: Christian Brauner <brauner@kernel.org>
Date: Thu, 12 Jun 2025 13:25:18 +0000 (+0200)
Subject: coredump: validate that path doesn't exceed UNIX_PATH_MAX
X-Git-Tag: block-6.17-20250808~61^2~1^2~20
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=3a2c977c463c68bf6fcd0138d15efa5f3adc743c;p=linux-block.git

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 70e37435eca9..a64b87878ab3 100644
--- 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;
 }