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authorHugh Dickins <hugh@veritas.com>2009-03-28 23:16:03 +0000
committerLinus Torvalds <torvalds@linux-foundation.org>2009-03-28 17:30:00 -0700
commit53e9309e01277ec99c38e84e0ca16921287cf470 (patch)
treebc70d617e1898e5b0fdf161edafa1808ae8fa529
parent07d43ba98621f08e252a48c96b258b4d572b0257 (diff)
compat_do_execve should unshare_files
2.6.26's commit fd8328be874f4190a811c58cd4778ec2c74d2c05 "sanitize handling of shared descriptor tables in failing execve()" moved the unshare_files() from flush_old_exec() and several binfmts to the head of do_execve(); but forgot to make the same change to compat_do_execve(), leaving a CLONE_FILES files_struct shared across exec from a 32-bit process on a 64-bit kernel. It's arguable whether the files_struct really ought to be unshared across exec; but 2.6.1 made that so to stop the loading binary's fd leaking into other threads, and a 32-bit process on a 64-bit kernel ought to behave in the same way as 32 on 32 and 64 on 64. Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/compat.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/fs/compat.c b/fs/compat.c
index 5e374aad33f..b543363dd62 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1420,12 +1420,17 @@ int compat_do_execve(char * filename,
{
struct linux_binprm *bprm;
struct file *file;
+ struct files_struct *displaced;
int retval;
+ retval = unshare_files(&displaced);
+ if (retval)
+ goto out_ret;
+
retval = -ENOMEM;
bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
if (!bprm)
- goto out_ret;
+ goto out_files;
retval = mutex_lock_interruptible(&current->cred_exec_mutex);
if (retval < 0)
@@ -1487,6 +1492,8 @@ int compat_do_execve(char * filename,
mutex_unlock(&current->cred_exec_mutex);
acct_update_integrals(current);
free_bprm(bprm);
+ if (displaced)
+ put_files_struct(displaced);
return retval;
out:
@@ -1506,6 +1513,9 @@ out_unlock:
out_free:
free_bprm(bprm);
+out_files:
+ if (displaced)
+ reset_files_struct(displaced);
out_ret:
return retval;
}