diff options
| author | Ross Lagerwall <ross.lagerwall@citrix.com> | 2019-01-08 18:30:56 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-20 10:13:21 +0100 |
| commit | 1f39e518cf9190422119a53a6d6964e800e7e789 (patch) | |
| tree | d8c3556c2b54df7e7f0bda31cdaeb651e696b267 /fs/cifs/file.c | |
| parent | 8347670127511f031d2e3503ae00a25d1956f19b (diff) | |
cifs: Limit memory used by lock request calls to a page
[ Upstream commit 92a8109e4d3a34fb6b115c9098b51767dc933444 ]
The code tries to allocate a contiguous buffer with a size supplied by
the server (maxBuf). This could fail if memory is fragmented since it
results in high order allocations for commonly used server
implementations. It is also wasteful since there are probably
few locks in the usual case. Limit the buffer to be no larger than a
page to avoid memory allocation failures due to fragmentation.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/cifs/file.c')
| -rw-r--r-- | fs/cifs/file.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 026b399af215..1062e96ee272 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -1081,6 +1081,10 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile) return -EINVAL; } + BUILD_BUG_ON(sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE) > + PAGE_SIZE); + max_buf = min_t(unsigned int, max_buf - sizeof(struct smb_hdr), + PAGE_SIZE); max_num = (max_buf - sizeof(struct smb_hdr)) / sizeof(LOCKING_ANDX_RANGE); buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL); @@ -1410,6 +1414,10 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, if (max_buf < (sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE))) return -EINVAL; + BUILD_BUG_ON(sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE) > + PAGE_SIZE); + max_buf = min_t(unsigned int, max_buf - sizeof(struct smb_hdr), + PAGE_SIZE); max_num = (max_buf - sizeof(struct smb_hdr)) / sizeof(LOCKING_ANDX_RANGE); buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL); |