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| author | Murphy Zhou <jencce.kernel@gmail.com> | 2019-05-23 12:12:43 +0800 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2019-05-28 19:11:35 -0500 |
| commit | 6457c20e336867fc90286d35bddcc9c0b0aaa936 (patch) | |
| tree | 9e545a3cd099b42f42683652c59dd11e5487b8b0 /fs/cifs | |
| parent | 210782038b54ec8e9059a3c12d6f6ae173efa3a9 (diff) | |
| download | linux-6457c20e336867fc90286d35bddcc9c0b0aaa936.tar.gz linux-6457c20e336867fc90286d35bddcc9c0b0aaa936.tar.bz2 linux-6457c20e336867fc90286d35bddcc9c0b0aaa936.zip | |
fs/cifs/smb2pdu.c: fix buffer free in SMB2_ioctl_free
The 2nd buffer could be NULL even if iov_len is not zero. This can
trigger a panic when handling symlinks. It's easy to reproduce with
LTP fs_racer scripts[1] which are randomly craete/delete/link files
and dirs. Fix this panic by checking if the 2nd buffer is padding
before kfree, like what we do in SMB2_open_free.
[1] https://github.com/linux-test-project/ltp/tree/master/testcases/kernel/fs/racer
Fixes: 2c87d6a94d16 ("cifs: Allocate memory for all iovs in smb2_ioctl")
Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie sahlberg <lsahlber@redhat.com>
Diffstat (limited to 'fs/cifs')
| -rw-r--r-- | fs/cifs/smb2pdu.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 5b8d1482ffbd..29b699d532ef 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -2620,10 +2620,12 @@ SMB2_ioctl_init(struct cifs_tcon *tcon, struct smb_rqst *rqst, void SMB2_ioctl_free(struct smb_rqst *rqst) { + int i; if (rqst && rqst->rq_iov) { cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */ - if (rqst->rq_iov[1].iov_len) - kfree(rqst->rq_iov[1].iov_base); + for (i = 1; i < rqst->rq_nvec; i++) + if (rqst->rq_iov[i].iov_base != smb2_padding) + kfree(rqst->rq_iov[i].iov_base); } } |