From: Ronnie Sahlberg lsahlber@redhat.com
commit 88a92c913cef09e70b1744a8877d177aa6cb2189 upstream.
RHBZ: 1722704
In low memory situations the various SMB2_*_init() functions can fail to allocate a request PDU and thus leave the request iovector as NULL.
If we don't check the return code for failure we end up calling smb2_set_next_command() with a NULL iovector causing a crash when it tries to dereference it.
CC: Stable stable@vger.kernel.org Signed-off-by: Ronnie Sahlberg lsahlber@redhat.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/cifs/smb2inode.c | 12 ++++++++++++ fs/cifs/smb2ops.c | 11 ++++++++++- 2 files changed, 22 insertions(+), 1 deletion(-)
--- a/fs/cifs/smb2inode.c +++ b/fs/cifs/smb2inode.c @@ -120,6 +120,8 @@ smb2_compound_op(const unsigned int xid, SMB2_O_INFO_FILE, 0, sizeof(struct smb2_file_all_info) + PATH_MAX * 2, 0, NULL); + if (rc) + goto finished; smb2_set_next_command(tcon, &rqst[num_rqst]); smb2_set_related(&rqst[num_rqst++]); trace_smb3_query_info_compound_enter(xid, ses->Suid, tcon->tid, @@ -147,6 +149,8 @@ smb2_compound_op(const unsigned int xid, COMPOUND_FID, current->tgid, FILE_DISPOSITION_INFORMATION, SMB2_O_INFO_FILE, 0, data, size); + if (rc) + goto finished; smb2_set_next_command(tcon, &rqst[num_rqst]); smb2_set_related(&rqst[num_rqst++]); trace_smb3_rmdir_enter(xid, ses->Suid, tcon->tid, full_path); @@ -163,6 +167,8 @@ smb2_compound_op(const unsigned int xid, COMPOUND_FID, current->tgid, FILE_END_OF_FILE_INFORMATION, SMB2_O_INFO_FILE, 0, data, size); + if (rc) + goto finished; smb2_set_next_command(tcon, &rqst[num_rqst]); smb2_set_related(&rqst[num_rqst++]); trace_smb3_set_eof_enter(xid, ses->Suid, tcon->tid, full_path); @@ -180,6 +186,8 @@ smb2_compound_op(const unsigned int xid, COMPOUND_FID, current->tgid, FILE_BASIC_INFORMATION, SMB2_O_INFO_FILE, 0, data, size); + if (rc) + goto finished; smb2_set_next_command(tcon, &rqst[num_rqst]); smb2_set_related(&rqst[num_rqst++]); trace_smb3_set_info_compound_enter(xid, ses->Suid, tcon->tid, @@ -206,6 +214,8 @@ smb2_compound_op(const unsigned int xid, COMPOUND_FID, current->tgid, FILE_RENAME_INFORMATION, SMB2_O_INFO_FILE, 0, data, size); + if (rc) + goto finished; smb2_set_next_command(tcon, &rqst[num_rqst]); smb2_set_related(&rqst[num_rqst++]); trace_smb3_rename_enter(xid, ses->Suid, tcon->tid, full_path); @@ -231,6 +241,8 @@ smb2_compound_op(const unsigned int xid, COMPOUND_FID, current->tgid, FILE_LINK_INFORMATION, SMB2_O_INFO_FILE, 0, data, size); + if (rc) + goto finished; smb2_set_next_command(tcon, &rqst[num_rqst]); smb2_set_related(&rqst[num_rqst++]); trace_smb3_hardlink_enter(xid, ses->Suid, tcon->tid, full_path); --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -2004,6 +2004,10 @@ smb2_set_related(struct smb_rqst *rqst) struct smb2_sync_hdr *shdr;
shdr = (struct smb2_sync_hdr *)(rqst->rq_iov[0].iov_base); + if (shdr == NULL) { + cifs_dbg(FYI, "shdr NULL in smb2_set_related\n"); + return; + } shdr->Flags |= SMB2_FLAGS_RELATED_OPERATIONS; }
@@ -2018,6 +2022,12 @@ smb2_set_next_command(struct cifs_tcon * unsigned long len = smb_rqst_len(server, rqst); int i, num_padding;
+ shdr = (struct smb2_sync_hdr *)(rqst->rq_iov[0].iov_base); + if (shdr == NULL) { + cifs_dbg(FYI, "shdr NULL in smb2_set_next_command\n"); + return; + } + /* SMB headers in a compound are 8 byte aligned. */
/* No padding needed */ @@ -2057,7 +2067,6 @@ smb2_set_next_command(struct cifs_tcon * }
finished: - shdr = (struct smb2_sync_hdr *)(rqst->rq_iov[0].iov_base); shdr->NextCommand = cpu_to_le32(len); }