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authorLeo Stone <leocstone@gmail.com>2024-12-17 10:26:57 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-02-17 10:04:49 +0100
commit36b385d0f2b4c0bf41d491e19075ecd990d2bf94 (patch)
tree34065d9764b247bd41c85783f355e57911fad3e5
parent52858d7fe6fbc804de1a48f7080fa50874d98f56 (diff)
safesetid: check size of policy writes
[ Upstream commit f09ff307c7299392f1c88f763299e24bc99811c7 ] syzbot attempts to write a buffer with a large size to a sysfs entry with writes handled by handle_policy_update(), triggering a warning in kmalloc. Check the size specified for write buffers before allocating. Reported-by: syzbot+4eb7a741b3216020043a@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=4eb7a741b3216020043a Signed-off-by: Leo Stone <leocstone@gmail.com> [PM: subject tweak] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--security/safesetid/securityfs.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/security/safesetid/securityfs.c b/security/safesetid/securityfs.c
index 25310468bcdd..8e1ffd70b18a 100644
--- a/security/safesetid/securityfs.c
+++ b/security/safesetid/securityfs.c
@@ -143,6 +143,9 @@ static ssize_t handle_policy_update(struct file *file,
char *buf, *p, *end;
int err;
+ if (len >= KMALLOC_MAX_SIZE)
+ return -EINVAL;
+
pol = kmalloc(sizeof(struct setid_ruleset), GFP_KERNEL);
if (!pol)
return -ENOMEM;