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author | Jeff Layton <jlayton@kernel.org> | 2023-03-17 20:13:08 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-30 13:49:04 +0300 |
commit | 51ddb84baff6f09ad62b5999ece3ec172e4e3568 (patch) | |
tree | 5d2de3cad01a79f89c106ad3fb422bba8496f0ac /drivers/dio | |
parent | 1c55982beb80c7d3c30278fc6cfda8496a31dbe6 (diff) | |
download | linux-51ddb84baff6f09ad62b5999ece3ec172e4e3568.tar.xz |
nfsd: don't replace page in rq_pages if it's a continuation of last page
[ Upstream commit 27c934dd8832dd40fd34776f916dc201e18b319b ]
The splice read calls nfsd_splice_actor to put the pages containing file
data into the svc_rqst->rq_pages array. It's possible however to get a
splice result that only has a partial page at the end, if (e.g.) the
filesystem hands back a short read that doesn't cover the whole page.
nfsd_splice_actor will plop the partial page into its rq_pages array and
return. Then later, when nfsd_splice_actor is called again, the
remainder of the page may end up being filled out. At this point,
nfsd_splice_actor will put the page into the array _again_ corrupting
the reply. If this is done enough times, rq_next_page will overrun the
array and corrupt the trailing fields -- the rq_respages and
rq_next_page pointers themselves.
If we've already added the page to the array in the last pass, don't add
it to the array a second time when dealing with a splice continuation.
This was originally handled properly in nfsd_splice_actor, but commit
91e23b1c3982 ("NFSD: Clean up nfsd_splice_actor()") removed the check
for it.
Fixes: 91e23b1c3982 ("NFSD: Clean up nfsd_splice_actor()")
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Dario Lesca <d.lesca@solinos.it>
Tested-by: David Critch <dcritch@redhat.com>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2150630
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/dio')
0 files changed, 0 insertions, 0 deletions