Messages in this thread | | | Date | Wed, 16 Apr 2008 22:13:36 +0400 | From | Cyrill Gorcunov <> | Subject | Re: [patch 1/3] NFS: fix potential NULL pointer dereference |
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[Trond Myklebust - Wed, Apr 16, 2008 at 02:11:31PM -0400] | | On Wed, 2008-04-16 at 21:44 +0400, Cyrill Gorcunov wrote: | > plain text document attachment (nfs-kstrdup-nul-fix) | > It's possible to get NULL pointer dereference | > if kstrndup failed | > | > Here is a possible scenario | > | > nfs4_get_sb | > nfs4_validate_mount_data | > o kstrndup failed so args->nfs_server.export_path = NULL | > nfs4_create_server | > nfs4_path_walk(..., NULL) -> Oops! | > | > Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> | | Why fix only the one case? What about the other kstrdup/kstrndup cases | in super.c that appear to be unchecked? | | Trond | | > --- | > | > Index: linux-2.6.git/fs/nfs/super.c | > =================================================================== | > --- linux-2.6.git.orig/fs/nfs/super.c 2008-04-15 23:01:30.000000000 +0400 | > +++ linux-2.6.git/fs/nfs/super.c 2008-04-16 20:01:44.000000000 +0400 | > @@ -1858,6 +1858,8 @@ static int nfs4_validate_mount_data(void | > if (len > NFS4_MAXPATHLEN) | > return -ENAMETOOLONG; | > args->nfs_server.export_path = kstrndup(c, len, GFP_KERNEL); | > + if (!args->nfs_server.export_path) | > + return -ENOMEM; | > | > dprintk("NFS: MNTPATH: '%s'\n", args->nfs_server.export_path); | > |
This one is leading to NULL deref, others - don't
- Cyrill -
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