linux/security
Sabyrzhan Tasbolatov 4ceb5ca9e6 smackfs: restrict bytes count in smackfs write functions
commit 7ef4c19d245f3dc233fd4be5acea436edd1d83d8 upstream.

syzbot found WARNINGs in several smackfs write operations where
bytes count is passed to memdup_user_nul which exceeds
GFP MAX_ORDER. Check count size if bigger than PAGE_SIZE.

Per smackfs doc, smk_write_net4addr accepts any label or -CIPSO,
smk_write_net6addr accepts any label or -DELETE. I couldn't find
any general rule for other label lengths except SMK_LABELLEN,
SMK_LONGLABEL, SMK_CIPSOMAX which are documented.

Let's constrain, in general, smackfs label lengths for PAGE_SIZE.
Although fuzzer crashes write to smackfs/netlabel on 0x400000 length.

Here is a quick way to reproduce the WARNING:
python -c "print('A' * 0x400000)" > /sys/fs/smackfs/netlabel

Reported-by: syzbot+a71a442385a0b2815497@syzkaller.appspotmail.com
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-07 12:20:42 +01:00
..
apparmor
integrity certs: Fix blacklist flag type confusion 2021-03-04 10:26:29 +01:00
keys KEYS: trusted: Fix migratable=1 failing 2021-03-04 10:26:44 +01:00
loadpin
lockdown
safesetid
selinux
smack smackfs: restrict bytes count in smackfs write functions 2021-03-07 12:20:42 +01:00
tomoyo
yama
Kconfig
Kconfig.hardening
Makefile
commoncap.c capabilities: Don't allow writing ambiguous v3 file capabilities 2021-03-04 10:26:26 +01:00
device_cgroup.c
inode.c
lsm_audit.c
min_addr.c
security.c