[PATCH -mm] Fix race between proc_readdir and remove_proc_entry

[Alexey Dobriyan]

> -procfs-fix-race-between-proc_readdir-and-remove_proc_entry.patch
> +fix-race-between-proc_get_inode-and-remove_proc_entry.patch
>
>  Updated.  Looks sane.

Why have you dropped the first patch? Resending slightly fixed version
of it.


[PATCH -mm] Fix race between proc_readdir and remove_proc_entry

From: "Darrick J. Wong" <[EMAIL PROTECTED]>

Fix the following race:

proc_readdirremove_proc_entry
=

spin_lock(_subdir_lock);
[choose PDE to start filldir from]
spin_unlock(_subdir_lock);
spin_lock(_subdir_lock);
[find PDE]
[free PDE, refcount is 0]
spin_unlock(_subdir_lock);
/* boom */
if (filldir(dirent, de->name, ...

[de_put on error path --adobriyan]

Signed-off-by: Darrick J. Wong <[EMAIL PROTECTED]>
Signed-off-by: Alexey Dobriyan <[EMAIL PROTECTED]>
---

 fs/proc/generic.c |   11 +--
 1 file changed, 9 insertions(+), 2 deletions(-)

--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -478,14 +478,21 @@ int proc_readdir(struct file * filp,
}
 
do {
+   struct proc_dir_entry *next;
+
/* filldir passes info to user space */
+   de_get(de);
spin_unlock(_subdir_lock);
if (filldir(dirent, de->name, de->namelen, 
filp->f_pos,
-   de->low_ino, de->mode >> 12) < 0)
+   de->low_ino, de->mode >> 12) < 0) {
+   de_put(de);
goto out;
+   }
spin_lock(_subdir_lock);
filp->f_pos++;
-   de = de->next;
+   next = de->next;
+   de_put(de);
+   de = next;
} while (de);
spin_unlock(_subdir_lock);
}

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[PATCH -mm] Fix race between proc_readdir and remove_proc_entry

[Alexey Dobriyan]

 -procfs-fix-race-between-proc_readdir-and-remove_proc_entry.patch
 +fix-race-between-proc_get_inode-and-remove_proc_entry.patch

  Updated.  Looks sane.

Why have you dropped the first patch? Resending slightly fixed version
of it.


[PATCH -mm] Fix race between proc_readdir and remove_proc_entry

From: Darrick J. Wong [EMAIL PROTECTED]

Fix the following race:

proc_readdirremove_proc_entry
=

spin_lock(proc_subdir_lock);
[choose PDE to start filldir from]
spin_unlock(proc_subdir_lock);
spin_lock(proc_subdir_lock);
[find PDE]
[free PDE, refcount is 0]
spin_unlock(proc_subdir_lock);
/* boom */
if (filldir(dirent, de-name, ...

[de_put on error path --adobriyan]

Signed-off-by: Darrick J. Wong [EMAIL PROTECTED]
Signed-off-by: Alexey Dobriyan [EMAIL PROTECTED]
---

 fs/proc/generic.c |   11 +--
 1 file changed, 9 insertions(+), 2 deletions(-)

--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -478,14 +478,21 @@ int proc_readdir(struct file * filp,
}
 
do {
+   struct proc_dir_entry *next;
+
/* filldir passes info to user space */
+   de_get(de);
spin_unlock(proc_subdir_lock);
if (filldir(dirent, de-name, de-namelen, 
filp-f_pos,
-   de-low_ino, de-mode  12)  0)
+   de-low_ino, de-mode  12)  0) {
+   de_put(de);
goto out;
+   }
spin_lock(proc_subdir_lock);
filp-f_pos++;
-   de = de-next;
+   next = de-next;
+   de_put(de);
+   de = next;
} while (de);
spin_unlock(proc_subdir_lock);
}

-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/