On Sat, Jan 4, 2025 at 7:49 PM Paul Moore [off-list ref] wrote:

On Wed, Dec 18, 2024 at 4:51 PM Paul Moore [off-list ref] wrote:

quoted

On Tue, Dec 17, 2024 at 1:27 PM Leo Stone [off-list ref] wrote:

quoted

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 <redacted>
---
v2: Make the check in handle_policy_update() to also cover
safesetid_uid_file_write(). Thanks for your feedback.
v1: https://lore.kernel.org/all/20241216030213.246804-2-leocstone@gmail.com/ (local)
---
 security/safesetid/securityfs.c | 3 +++
 1 file changed, 3 insertions(+)

Looks okay to me.  Micah, are you planning to merge this patch, or
would you like me to take it via the LSM tree?

Reviewed-by: Paul Moore <paul@paul-moore.com>

I'm going to tag this to come back to it in a week or so in case we
don't hear from Micah, but if you don't see any further replies Leo,
feel free to send a gentle nudge ;)

I'm going to go ahead and merge this into lsm/dev, if Micah has a
problem with that I can always remove/revert if needed.

We may need to revisit safesetid's documented support status, but
that's a topic for another day.

Sorry guys, I missed this one. I usually just check in weekly on my
linux-security-users filter in my email inbox and see if any
discussions include 'SafeSetID'.

I must have skimmed over 'lsm: check size of writes' thinking it was a
generic LSM patch rather than something specific to SafeSetID.

I'll have to adjust my email settings so that emails which directly
list me on the CC are sent to a specific folder for me to check more
closely.

Micah

Thanks everyone.

--
paul-moore.com