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| author | Kinglong Mee <kinglongmee@gmail.com> | 2014-05-23 19:57:49 +0800 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2014-05-30 17:32:18 -0400 |
| commit | a1f05514b016aeaed638dbf677f443af7e7bde4f (patch) | |
| tree | 92f0b908e551cf832e1ebda31724a3d898575ee9 | |
| parent | a5cddc885b99458df963a75abbe0b40cbef56c48 (diff) | |
| download | linux-a1f05514b016aeaed638dbf677f443af7e7bde4f.tar.bz2 | |
NFS4: Avoid NULL reference or double free in nfsd4_fslocs_free()
If fsloc_parse() failed at kzalloc(), fs/nfsd/export.c
411
412 fsloc->locations = kzalloc(fsloc->locations_count
413 * sizeof(struct nfsd4_fs_location), GFP_KERNEL);
414 if (!fsloc->locations)
415 return -ENOMEM;
svc_export_parse() will call nfsd4_fslocs_free() with fsloc->locations = NULL,
so that, "kfree(fsloc->locations[i].path);" will cause a crash.
If fsloc_parse() failed after that, fsloc_parse() will call nfsd4_fslocs_free(),
and svc_export_parse() will call it again, so that, a double free is caused.
This patch checks the fsloc->locations, and set to NULL after it be freed.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| -rw-r--r-- | fs/nfsd/export.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c index 8513c598fabf..9a41d3ddd8df 100644 --- a/fs/nfsd/export.c +++ b/fs/nfsd/export.c @@ -295,13 +295,19 @@ svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new, static void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc) { + struct nfsd4_fs_location *locations = fsloc->locations; int i; + if (!locations) + return; + for (i = 0; i < fsloc->locations_count; i++) { - kfree(fsloc->locations[i].path); - kfree(fsloc->locations[i].hosts); + kfree(locations[i].path); + kfree(locations[i].hosts); } - kfree(fsloc->locations); + + kfree(locations); + fsloc->locations = NULL; } static void svc_export_put(struct kref *ref) |