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CRED: Rename cred_exec_mutex to reflect that it's a guard against ptrace

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Rename cred_exec_mutex to reflect that it's a guard against foreign
intervention on a process's credential state, such as is made by ptrace().  The
attachment of a debugger to a process affects execve()'s calculation of the new
credential state - _and_ also setprocattr()'s calculation of that state.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
This commit is contained in:
David Howells
2009-05-08 13:55:22 +01:00
committed by James Morris
parent d254117099
commit 5e751e992f
6 changed files with 20 additions and 17 deletions
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10
fs/exec.c
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@@ -1045,7 +1045,7 @@ void install_exec_creds(struct linux_binprm *bprm)
commit_creds(bprm->cred);
bprm->cred = NULL;
/* cred_exec_mutex must be held at least to this point to prevent
/* cred_guard_mutex must be held at least to this point to prevent
* ptrace_attach() from altering our determination of the task's
* credentials; any time after this it may be unlocked */
@@ -1055,7 +1055,7 @@ EXPORT_SYMBOL(install_exec_creds);
/*
* determine how safe it is to execute the proposed program
* - the caller must hold current->cred_exec_mutex to protect against
* - the caller must hold current->cred_guard_mutex to protect against
* PTRACE_ATTACH
*/
int check_unsafe_exec(struct linux_binprm *bprm)
@@ -1297,7 +1297,7 @@ int do_execve(char * filename,
if (!bprm)
goto out_files;
retval = mutex_lock_interruptible(&current->cred_exec_mutex);
retval = mutex_lock_interruptible(&current->cred_guard_mutex);
if (retval < 0)
goto out_free;
current->in_execve = 1;
@@ -1360,7 +1360,7 @@ int do_execve(char * filename,
/* execve succeeded */
current->fs->in_exec = 0;
current->in_execve = 0;
mutex_unlock(&current->cred_exec_mutex);
mutex_unlock(&current->cred_guard_mutex);
acct_update_integrals(current);
free_bprm(bprm);
if (displaced)
@@ -1383,7 +1383,7 @@ out_unmark:
out_unlock:
current->in_execve = 0;
mutex_unlock(&current->cred_exec_mutex);
mutex_unlock(&current->cred_guard_mutex);
out_free:
free_bprm(bprm);