diff options
| author | Andrew Morton <akpm@digeo.com> | 2003-02-02 06:06:58 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@home.transmeta.com> | 2003-02-02 06:06:58 -0800 |
| commit | 3b149cc7cd1573436468c1103b2f42f3fd0888a4 (patch) | |
| tree | abd74772fb0919192d325651eb5a06ff7c636180 /security | |
| parent | db54e7429f54d4dc1b8d8bb1c59b0391cd75628b (diff) | |
| download | history-3b149cc7cd1573436468c1103b2f42f3fd0888a4.tar.gz | |
[PATCH] remove lock_kernel() from exec of setuid apps
Patch from Manfred Spraul <manfred@colorfullife.com>
exec of setuid apps and ptrace must be synchronized, to ensure that a normal
user cannot ptrace a setuid app across exec. ptrace_attach acquires the
task_lock around the uid checks, compute_creds acquires the BLK. The patch
converts compute_creds to the task_lock. Additionally, it removes the
do_unlock variable: the task_lock is not heaviliy used, there is no need to
avoid the spinlock by adding branches.
The patch is a cleanup patch, not a fix for a security problem: AFAICS the
sys_ptrace in every arch acquires the BKL before calling ptrace_attach.
Diffstat (limited to 'security')
| -rw-r--r-- | security/capability.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/security/capability.c b/security/capability.c index 8e26f1f52b1afe..cf6d2440a21d21 100644 --- a/security/capability.c +++ b/security/capability.c @@ -120,17 +120,16 @@ void cap_bprm_compute_creds (struct linux_binprm *bprm) { /* Derived from fs/exec.c:compute_creds. */ kernel_cap_t new_permitted, working; - int do_unlock = 0; new_permitted = cap_intersect (bprm->cap_permitted, cap_bset); working = cap_intersect (bprm->cap_inheritable, current->cap_inheritable); new_permitted = cap_combine (new_permitted, working); + task_lock(current); if (!cap_issubset (new_permitted, current->cap_permitted)) { current->mm->dumpable = 0; - lock_kernel (); if (must_not_trace_exec (current) || atomic_read (¤t->fs->count) > 1 || atomic_read (¤t->files->count) > 1 @@ -141,7 +140,6 @@ void cap_bprm_compute_creds (struct linux_binprm *bprm) cap_permitted); } } - do_unlock = 1; } /* For init, we want to retain the capabilities set @@ -154,9 +152,7 @@ void cap_bprm_compute_creds (struct linux_binprm *bprm) } /* AUD: Audit candidate if current->cap_effective is set */ - - if (do_unlock) - unlock_kernel (); + task_unlock(current); current->keep_capabilities = 0; } |