6.12-stable review patch. If anyone has any objections, please let me know.
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From: Stephen Smalley stephen.smalley.work@gmail.com
[ Upstream commit fde46f60f6c5138ee422087addbc5bf5b4968bf1 ]
If the end result of a security_compute_sid() computation matches the ssid or tsid, return that SID rather than looking it up again. This avoids the problem of multiple initial SIDs that map to the same context.
Cc: stable@vger.kernel.org Reported-by: Guido Trentalancia guido@trentalancia.com Fixes: ae254858ce07 ("selinux: introduce an initial SID for early boot processes") Signed-off-by: Stephen Smalley stephen.smalley.work@gmail.com Tested-by: Guido Trentalancia guido@trentalancia.com Signed-off-by: Paul Moore paul@paul-moore.com Signed-off-by: Sasha Levin sashal@kernel.org --- security/selinux/ss/services.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 88850405ded92..f36332e64c4d1 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -1884,11 +1884,17 @@ static int security_compute_sid(u32 ssid, goto out_unlock; } /* Obtain the sid for the context. */ - rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); - if (rc == -ESTALE) { - rcu_read_unlock(); - context_destroy(&newcontext); - goto retry; + if (context_cmp(scontext, &newcontext)) + *out_sid = ssid; + else if (context_cmp(tcontext, &newcontext)) + *out_sid = tsid; + else { + rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + context_destroy(&newcontext); + goto retry; + } } out_unlock: rcu_read_unlock();