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CVE-2012-1090 CIFS: fix dentry refcount leak when opening a FIFO on lookup (rhbz 798296)

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Justin M. Forbes 2012-02-28 14:14:22 -06:00
parent e0d8aaf397
commit 4d8a6ac05d
2 changed files with 70 additions and 0 deletions
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61
cifs-fix-dentry-refcount-leak-when-opening-a-FIFO.patch Normal file
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@ -0,0 +1,61 @@
From 5bccda0ebc7c0331b81ac47d39e4b920b198b2cd Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@redhat.com>
Date: Thu, 23 Feb 2012 09:37:45 -0500
Subject: [PATCH] cifs: fix dentry refcount leak when opening a FIFO on lookup
The cifs code will attempt to open files on lookup under certain
circumstances. What happens though if we find that the file we opened
was actually a FIFO or other special file?
Currently, the open filehandle just ends up being leaked leading to
a dentry refcount mismatch and oops on umount. Fix this by having the
code close the filehandle on the server if it turns out not to be a
regular file. While we're at it, change this spaghetti if statement
into a switch too.
Cc: stable@vger.kernel.org
Reported-by: CAI Qian <caiqian@redhat.com>
Tested-by: CAI Qian <caiqian@redhat.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
---
fs/cifs/dir.c | 20 ++++++++++++++++++--
1 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 63a196b..bc7e244 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -584,10 +584,26 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
* If either that or op not supported returned, follow
* the normal lookup.
*/
- if ((rc == 0) || (rc == -ENOENT))
+ switch (rc) {
+ case 0:
+ /*
+ * The server may allow us to open things like
+ * FIFOs, but the client isn't set up to deal
+ * with that. If it's not a regular file, just
+ * close it and proceed as if it were a normal
+ * lookup.
+ */
+ if (newInode && !S_ISREG(newInode->i_mode)) {
+ CIFSSMBClose(xid, pTcon, fileHandle);
+ break;
+ }
+ case -ENOENT:
posix_open = true;
- else if ((rc == -EINVAL) || (rc != -EOPNOTSUPP))
+ case -EOPNOTSUPP:
+ break;
+ default:
pTcon->broken_posix_open = true;
+ }
}
if (!posix_open)
rc = cifs_get_inode_info_unix(&newInode, full_path,
--
1.7.0.4

9
kernel.spec
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@ -774,6 +774,9 @@ Patch21280: ums_realtek-do-not-use-stack-memory-for-DMA-in-__do_.patch
#rhbz 727865 730007
Patch21300: ACPICA-Fix-regression-in-FADT-revision-checks.patch
#rhbz 798296
Patch21301: cifs-fix-dentry-refcount-leak-when-opening-a-FIFO.patch
# compat-wireless patches
Patch50000: compat-wireless-config-fixups.patch
Patch50001: compat-wireless-pr_fmt-warning-avoidance.patch
@ -1493,6 +1496,9 @@ ApplyPatch ums_realtek-do-not-use-stack-memory-for-DMA-in-__do_.patch
#rhbz 727865 730007
ApplyPatch ACPICA-Fix-regression-in-FADT-revision-checks.patch
#rhbz 798296
ApplyPatch cifs-fix-dentry-refcount-leak-when-opening-a-FIFO.patch
# END OF PATCH APPLICATIONS
%endif
@ -2364,6 +2370,9 @@ fi
# ||----w |
# || ||
%changelog
* Tue Feb 28 2012 Justin M. Forbes <jforbes@redhat.com>
- CVE-2012-1090 CIFS: fix dentry refcount leak when opening a FIFO on lookup (rhbz 798296)
* Tue Feb 28 2012 Dave Jones <davej@redhat.com> - 3.3.0-0.rc5.git2.1
- Linux v3.3-rc5-88-g586c6e7