* [PATCH AUTOSEL 6.12 28/31] safesetid: check size of policy writes
[not found] <20250126145448.930220-1-sashal@kernel.org>
@ 2025-01-26 14:54 ` Sasha Levin
0 siblings, 0 replies; only message in thread
From: Sasha Levin @ 2025-01-26 14:54 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Leo Stone, syzbot+4eb7a741b3216020043a, Paul Moore, Sasha Levin,
mortonm, jmorris, serge, linux-security-module
From: Leo Stone <leocstone@gmail.com>
[ 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>
---
security/safesetid/securityfs.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/security/safesetid/securityfs.c b/security/safesetid/securityfs.c
index 25310468bcddf..8e1ffd70b18ab 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;
--
2.39.5
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