The patch titled
From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx>
has been added to the -mm tree. Its filename is
c-r-prctl-less-paranoid-prctl_set_mm_exe_file.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx>
Subject: c/r: prctl: less paranoid prctl_set_mm_exe_file()
"no other files mapped" requirement from my previous patch (c/r: prctl:
update prctl_set_mm_exe_file() after mm->num_exe_file_vmas removal) is too
paranoid, it forbids operation even if there mapped one shared-anon vma.
Let's check that current mm->exe_file already unmapped, in this case
exe_file symlink already outdated and its changing is reasonable.
Plus, this patch fixes exit code in case operation success.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx>
Reported-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
Tested-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Matt Helsley <matthltc@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/sys.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff -puN kernel/sys.c~c-r-prctl-less-paranoid-prctl_set_mm_exe_file kernel/sys.c
--- a/kernel/sys.c~c-r-prctl-less-paranoid-prctl_set_mm_exe_file
+++ a/kernel/sys.c
@@ -1788,7 +1788,6 @@ SYSCALL_DEFINE1(umask, int, mask)
#ifdef CONFIG_CHECKPOINT_RESTORE
static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
{
- struct vm_area_struct *vma;
struct file *exe_file;
struct dentry *dentry;
int err;
@@ -1816,13 +1815,17 @@ static int prctl_set_mm_exe_file(struct
down_write(&mm->mmap_sem);
/*
- * Forbid mm->exe_file change if there are mapped other files.
+ * Forbid mm->exe_file change if old file still mapped.
*/
err = -EBUSY;
- for (vma = mm->mmap; vma; vma = vma->vm_next) {
- if (vma->vm_file && !path_equal(&vma->vm_file->f_path,
- &exe_file->f_path))
- goto exit_unlock;
+ if (mm->exe_file) {
+ struct vm_area_struct *vma;
+
+ for (vma = mm->mmap; vma; vma = vma->vm_next)
+ if (vma->vm_file &&
+ path_equal(&vma->vm_file->f_path,
+ &mm->exe_file->f_path))
+ goto exit_unlock;
}
/*
@@ -1835,6 +1838,7 @@ static int prctl_set_mm_exe_file(struct
if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags))
goto exit_unlock;
+ err = 0;
set_mm_exe_file(mm, exe_file);
exit_unlock:
up_write(&mm->mmap_sem);
_
Subject: From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx>
Patches currently in -mm which might be from khlebnikov@xxxxxxxxxx are
linux-next.patch
memcg-fix-use_hierarchy-css_is_ancestor-oops-regression.patch
mm-correctly-synchronize-rss-counters-at-exit-exec.patch
c-r-prctl-less-paranoid-prctl_set_mm_exe_file.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
