smb: client: fix OOB in receive_encrypted_standard()
commit eec04ea119691e65227a97ce53c0da6b9b74b0b7 upstream.
Fix potential OOB in receive_encrypted_standard() if server returned a
large shdr->NextCommand that would end up writing off the end of
@next_buffer.
Fixes: b24df3e30c
("cifs: update receive_encrypted_standard to handle compounded responses")
Cc: stable@vger.kernel.org
Reported-by: Robert Morris <rtm@csail.mit.edu>
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
4029b025be
commit
534733397d
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@ -4941,6 +4941,7 @@ receive_encrypted_standard(struct TCP_Server_Info *server,
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struct smb2_hdr *shdr;
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unsigned int pdu_length = server->pdu_size;
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unsigned int buf_size;
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unsigned int next_cmd;
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struct mid_q_entry *mid_entry;
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int next_is_large;
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char *next_buffer = NULL;
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@ -4969,14 +4970,15 @@ receive_encrypted_standard(struct TCP_Server_Info *server,
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next_is_large = server->large_buf;
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one_more:
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shdr = (struct smb2_hdr *)buf;
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if (shdr->NextCommand) {
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next_cmd = le32_to_cpu(shdr->NextCommand);
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if (next_cmd) {
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if (WARN_ON_ONCE(next_cmd > pdu_length))
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return -1;
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if (next_is_large)
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next_buffer = (char *)cifs_buf_get();
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else
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next_buffer = (char *)cifs_small_buf_get();
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memcpy(next_buffer,
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buf + le32_to_cpu(shdr->NextCommand),
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pdu_length - le32_to_cpu(shdr->NextCommand));
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memcpy(next_buffer, buf + next_cmd, pdu_length - next_cmd);
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}
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mid_entry = smb2_find_mid(server, buf);
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@ -5000,8 +5002,8 @@ one_more:
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else
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ret = cifs_handle_standard(server, mid_entry);
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if (ret == 0 && shdr->NextCommand) {
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pdu_length -= le32_to_cpu(shdr->NextCommand);
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if (ret == 0 && next_cmd) {
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pdu_length -= next_cmd;
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server->large_buf = next_is_large;
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if (next_is_large)
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server->bigbuf = buf = next_buffer;
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