Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Fri, 13 Jun 2003 00:22:24 -0700 | From | Chris Wright <> | Subject | Re: [PATCH][LSM] setfsuid/setgsuid bug fix 4/4 |
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Patch from Jakub Jelínek <jakub@redhat.com>
[LSM] make sure setfsuid/setfsgid return values are right. Before include/linux/security.h was added, setfsuid/setfsgid always returned old_fsuid, no matter if the fsuid was actually changed or not. With the default security ops it seems to do the same, because both security_task_setuid and security_task_post_setuid return 0, but these are hooks which seem to return 0 on success, -errno on failure, so if some non-default security hook is installed and ever returns -errno in setfsuid/setfsgid, -errno will be returned from the syscall instead of the expected old_fsuid. This makes it hard to distinguish uids 0xfffff001 .. 0xffffffff from errors of security hooks.
--- linus-2.5/kernel/sys.c.setfsuid Thu Jun 12 22:53:14 2003 +++ linus-2.5/kernel/sys.c Thu Jun 12 22:53:14 2003 @@ -831,13 +831,11 @@ asmlinkage long sys_setfsuid(uid_t uid) { int old_fsuid; - int retval; - - retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS); - if (retval) - return retval; old_fsuid = current->fsuid; + if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS)) + return old_fsuid; + if (uid == current->uid || uid == current->euid || uid == current->suid || uid == current->fsuid || capable(CAP_SETUID)) @@ -850,9 +848,7 @@ current->fsuid = uid; } - retval = security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS); - if (retval) - return retval; + security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS); return old_fsuid; } @@ -863,13 +859,11 @@ asmlinkage long sys_setfsgid(gid_t gid) { int old_fsgid; - int retval; - - retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS); - if (retval) - return retval; old_fsgid = current->fsgid; + if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS)) + return old_fsgid; + if (gid == current->gid || gid == current->egid || gid == current->sgid || gid == current->fsgid || capable(CAP_SETGID)) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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