6.6-stable review patch. If anyone has any objections, please let me know.
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From: Meetakshi Setiya msetiya@microsoft.com
commit b9aef1b13a0a92aa7058ba235afb24b5b89153ca upstream.
Fixes the case for example where the password specified on mount is a recently expired password, but password2 is valid. Without this patch this mount scenario would fail.
This patch introduces the following changes to support password rotation on mount:
1. If an existing session is not found and the new session setup results in EACCES, EKEYEXPIRED or EKEYREVOKED, swap password and password2 (if available), and retry the mount.
2. To match the new mount with an existing session, add conditions to check if a) password and password2 of the new mount and the existing session are the same, or b) password of the new mount is the same as the password2 of the existing session, and password2 of the new mount is the same as the password of the existing session.
3. If an existing session is found, but needs reconnect, retry the session setup after swapping password and password2 (if available), in case the previous attempt results in EACCES, EKEYEXPIRED or EKEYREVOKED.
Cc: stable@vger.kernel.org Signed-off-by: Meetakshi Setiya msetiya@microsoft.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/smb/client/connect.c | 57 ++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 50 insertions(+), 7 deletions(-)
--- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -1908,11 +1908,35 @@ static int match_session(struct cifs_ses CIFS_MAX_USERNAME_LEN)) return 0; if ((ctx->username && strlen(ctx->username) != 0) && - ses->password != NULL && - strncmp(ses->password, - ctx->password ? ctx->password : "", - CIFS_MAX_PASSWORD_LEN)) - return 0; + ses->password != NULL) { + + /* New mount can only share sessions with an existing mount if: + * 1. Both password and password2 match, or + * 2. password2 of the old mount matches password of the new mount + * and password of the old mount matches password2 of the new + * mount + */ + if (ses->password2 != NULL && ctx->password2 != NULL) { + if (!((strncmp(ses->password, ctx->password ? + ctx->password : "", CIFS_MAX_PASSWORD_LEN) == 0 && + strncmp(ses->password2, ctx->password2, + CIFS_MAX_PASSWORD_LEN) == 0) || + (strncmp(ses->password, ctx->password2, + CIFS_MAX_PASSWORD_LEN) == 0 && + strncmp(ses->password2, ctx->password ? + ctx->password : "", CIFS_MAX_PASSWORD_LEN) == 0))) + return 0; + + } else if ((ses->password2 == NULL && ctx->password2 != NULL) || + (ses->password2 != NULL && ctx->password2 == NULL)) { + return 0; + + } else { + if (strncmp(ses->password, ctx->password ? + ctx->password : "", CIFS_MAX_PASSWORD_LEN)) + return 0; + } + } }
if (strcmp(ctx->local_nls->charset, ses->local_nls->charset)) @@ -2256,6 +2280,7 @@ struct cifs_ses * cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) { int rc = 0; + int retries = 0; unsigned int xid; struct cifs_ses *ses; struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr; @@ -2274,6 +2299,8 @@ cifs_get_smb_ses(struct TCP_Server_Info cifs_dbg(FYI, "Session needs reconnect\n");
mutex_lock(&ses->session_mutex); + +retry_old_session: rc = cifs_negotiate_protocol(xid, ses, server); if (rc) { mutex_unlock(&ses->session_mutex); @@ -2286,6 +2313,13 @@ cifs_get_smb_ses(struct TCP_Server_Info rc = cifs_setup_session(xid, ses, server, ctx->local_nls); if (rc) { + if (((rc == -EACCES) || (rc == -EKEYEXPIRED) || + (rc == -EKEYREVOKED)) && !retries && ses->password2) { + retries++; + cifs_dbg(FYI, "Session reconnect failed, retrying with alternate password\n"); + swap(ses->password, ses->password2); + goto retry_old_session; + } mutex_unlock(&ses->session_mutex); /* problem -- put our reference */ cifs_put_smb_ses(ses); @@ -2361,6 +2395,7 @@ cifs_get_smb_ses(struct TCP_Server_Info ses->chans_need_reconnect = 1; spin_unlock(&ses->chan_lock);
+retry_new_session: mutex_lock(&ses->session_mutex); rc = cifs_negotiate_protocol(xid, ses, server); if (!rc) @@ -2373,8 +2408,16 @@ cifs_get_smb_ses(struct TCP_Server_Info sizeof(ses->smb3signingkey)); spin_unlock(&ses->chan_lock);
- if (rc) - goto get_ses_fail; + if (rc) { + if (((rc == -EACCES) || (rc == -EKEYEXPIRED) || + (rc == -EKEYREVOKED)) && !retries && ses->password2) { + retries++; + cifs_dbg(FYI, "Session setup failed, retrying with alternate password\n"); + swap(ses->password, ses->password2); + goto retry_new_session; + } else + goto get_ses_fail; + }
/* * success, put it on the list and add it as first channel