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| author | Greg Kurz <groug@kaod.org> | 2017-02-26 23:42:43 +0100 |
|---|---|---|
| committer | Greg Kurz <groug@kaod.org> | 2017-02-28 11:21:15 +0100 |
| commit | 3e36aba757f76673007a80b3cd56a4062c2e3462 (patch) | |
| tree | fde3ba123eb07da546df251adc8fc3c710949735 /hw/9pfs/9p-util.h | |
| parent | 5507904e362df252f6065cb27d1ff98372db6abc (diff) | |
| download | qemu-3e36aba757f76673007a80b3cd56a4062c2e3462.zip qemu-3e36aba757f76673007a80b3cd56a4062c2e3462.tar.gz qemu-3e36aba757f76673007a80b3cd56a4062c2e3462.tar.bz2 | |
9pfs: local: lsetxattr: don't follow symlinks
The local_lsetxattr() callback is vulnerable to symlink attacks because
it calls lsetxattr() which follows symbolic links in all path elements but
the rightmost one.
This patch introduces a helper to emulate the non-existing fsetxattrat()
function: it is implemented with /proc/self/fd which provides a trusted
path that can be safely passed to lsetxattr().
local_lsetxattr() is converted to use this helper and opendir_nofollow().
This partly fixes CVE-2016-9602.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'hw/9pfs/9p-util.h')
| -rw-r--r-- | hw/9pfs/9p-util.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/hw/9pfs/9p-util.h b/hw/9pfs/9p-util.h index 676641f..091f3ce 100644 --- a/hw/9pfs/9p-util.h +++ b/hw/9pfs/9p-util.h @@ -48,5 +48,7 @@ int relative_openat_nofollow(int dirfd, const char *path, int flags, mode_t mode); ssize_t fgetxattrat_nofollow(int dirfd, const char *path, const char *name, void *value, size_t size); +int fsetxattrat_nofollow(int dirfd, const char *path, const char *name, + void *value, size_t size, int flags); #endif |