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author | NeilBrown <neilb@suse.com> | 2019-04-05 11:34:40 +1100 |
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committer | J. Bruce Fields <bfields@redhat.com> | 2019-04-05 19:57:24 -0400 |
commit | d58431eacb226222430940134d97bfd72f292fcd (patch) | |
tree | 92c165aeccfb3dcc3918746317774fef2ba0ac99 /fs/nfsd | |
parent | 79a3aaa7b82e3106be97842dedfd8429248896e6 (diff) | |
download | linux-d58431eacb226222430940134d97bfd72f292fcd.tar.bz2 |
sunrpc: don't mark uninitialised items as VALID.
A recent commit added a call to cache_fresh_locked()
when an expired item was found.
The call sets the CACHE_VALID flag, so it is important
that the item actually is valid.
There are two ways it could be valid:
1/ If ->update has been called to fill in relevant content
2/ if CACHE_NEGATIVE is set, to say that content doesn't exist.
An expired item that is waiting for an update will be neither.
Setting CACHE_VALID will mean that a subsequent call to cache_put()
will be likely to dereference uninitialised pointers.
So we must make sure the item is valid, and we already have code to do
that in try_to_negate_entry(). This takes the hash lock and so cannot
be used directly, so take out the two lines that we need and use them.
Now cache_fresh_locked() is certain to be called only on
a valid item.
Cc: stable@kernel.org # 2.6.35
Fixes: 4ecd55ea0742 ("sunrpc: fix cache_head leak due to queued request")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs/nfsd')
0 files changed, 0 insertions, 0 deletions