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| author | Bryam Vargas <hexlabsecurity@proton.me> | 2026-07-31 20:44:09 +0300 |
|---|---|---|
| committer | Paul Moore <paul@paul-moore.com> | 2026-08-03 23:03:55 +0300 |
| commit | e5c0235a3c4e9eb047a16cd02323fe4ecf2f570e (patch) | |
| tree | eeffd25104bbbc44c284787becfa8fb259c5b323 | |
| parent | 28254722a459938d97150d3b0712b81e06d0645e (diff) | |
| download | linux-e5c0235a3c4e9eb047a16cd02323fe4ecf2f570e.tar.xz | |
selinux: do not cancel a policy conversion that never started
sel_write_load() calls selinux_policy_cancel() when sel_make_policy_nodes()
fails, and that helper dereferences the outgoing policy to cancel its
sidtab conversion. On the first policy load there is no outgoing policy:
security_load_policy() returns early for that case, before it converts
anything, and state->policy is still NULL. A first load that fails while
building the selinuxfs tree therefore takes a NULL dereference in
selinux_policy_cancel(), reached from a write(2) to /sys/fs/selinux/load.
Skip the cancel when there is no old policy, mirroring the check
security_load_policy() already makes before it converts.
Cc: stable@vger.kernel.org
Fixes: 02a52c5c8c3b ("selinux: move policy commit after updating selinuxfs")
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
| -rw-r--r-- | security/selinux/ss/services.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 2d828548f3db..90e81186cb2e 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -2221,7 +2221,9 @@ void selinux_policy_cancel(struct selinux_load_state *load_state) oldpolicy = rcu_dereference_protected(state->policy, lockdep_is_held(&state->policy_mutex)); - sidtab_cancel_convert(oldpolicy->sidtab); + /* a first load has no outgoing policy and converted nothing */ + if (oldpolicy) + sidtab_cancel_convert(oldpolicy->sidtab); selinux_policy_free(load_state->policy); kfree(load_state->convert_data); } |