diff options
| author | Mark Mielke <mark.mielke@gmail.com> | 2020-09-28 00:33:29 -0400 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2020-09-29 23:09:19 -0400 |
| commit | bcf3a2953d36bbfb9bd44ccb3db0897d935cc485 (patch) | |
| tree | 106b1dc9736cd1e3310d68c0beaaee4627b2b5f5 /drivers/scsi/iscsi_tcp.c | |
| parent | 149415586243bd0ea729760fb6dd7b3c50601871 (diff) | |
| download | linux-bcf3a2953d36bbfb9bd44ccb3db0897d935cc485.tar.bz2 | |
scsi: iscsi: iscsi_tcp: Avoid holding spinlock while calling getpeername()
The kernel may fail to boot or devices may fail to come up when
initializing iscsi_tcp devices starting with Linux 5.8.
Commit a79af8a64d39 ("[SCSI] iscsi_tcp: use iscsi_conn_get_addr_param
libiscsi function") introduced getpeername() within the session spinlock.
Commit 1b66d253610c ("bpf: Add get{peer, sock}name attach types for
sock_addr") introduced BPF_CGROUP_RUN_SA_PROG_LOCK() within getpeername(),
which acquires a mutex and when used from iscsi_tcp devices can now lead to
"BUG: scheduling while atomic:" and subsequent damage.
Ensure that the spinlock is released before calling getpeername() or
getsockname(). sock_hold() and sock_put() are used to ensure that the
socket reference is preserved until after the getpeername() or
getsockname() complete.
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1877345
Link: https://lkml.org/lkml/2020/7/28/1085
Link: https://lkml.org/lkml/2020/8/31/459
Link: https://lore.kernel.org/r/20200928043329.606781-1-mark.mielke@gmail.com
Fixes: a79af8a64d39 ("[SCSI] iscsi_tcp: use iscsi_conn_get_addr_param libiscsi function")
Fixes: 1b66d253610c ("bpf: Add get{peer, sock}name attach types for sock_addr")
Cc: stable@vger.kernel.org
Reported-by: Marc Dionne <marc.c.dionne@gmail.com>
Tested-by: Marc Dionne <marc.c.dionne@gmail.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Mark Mielke <mark.mielke@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/iscsi_tcp.c')
| -rw-r--r-- | drivers/scsi/iscsi_tcp.c | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c index b5dd1caae5e9..d10efb66cf19 100644 --- a/drivers/scsi/iscsi_tcp.c +++ b/drivers/scsi/iscsi_tcp.c @@ -736,6 +736,7 @@ static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn, struct iscsi_tcp_conn *tcp_conn = conn->dd_data; struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; struct sockaddr_in6 addr; + struct socket *sock; int rc; switch(param) { @@ -747,13 +748,17 @@ static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn, spin_unlock_bh(&conn->session->frwd_lock); return -ENOTCONN; } + sock = tcp_sw_conn->sock; + sock_hold(sock->sk); + spin_unlock_bh(&conn->session->frwd_lock); + if (param == ISCSI_PARAM_LOCAL_PORT) - rc = kernel_getsockname(tcp_sw_conn->sock, + rc = kernel_getsockname(sock, (struct sockaddr *)&addr); else - rc = kernel_getpeername(tcp_sw_conn->sock, + rc = kernel_getpeername(sock, (struct sockaddr *)&addr); - spin_unlock_bh(&conn->session->frwd_lock); + sock_put(sock->sk); if (rc < 0) return rc; @@ -775,6 +780,7 @@ static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost, struct iscsi_tcp_conn *tcp_conn; struct iscsi_sw_tcp_conn *tcp_sw_conn; struct sockaddr_in6 addr; + struct socket *sock; int rc; switch (param) { @@ -789,16 +795,18 @@ static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost, return -ENOTCONN; } tcp_conn = conn->dd_data; - tcp_sw_conn = tcp_conn->dd_data; - if (!tcp_sw_conn->sock) { + sock = tcp_sw_conn->sock; + if (!sock) { spin_unlock_bh(&session->frwd_lock); return -ENOTCONN; } + sock_hold(sock->sk); + spin_unlock_bh(&session->frwd_lock); - rc = kernel_getsockname(tcp_sw_conn->sock, + rc = kernel_getsockname(sock, (struct sockaddr *)&addr); - spin_unlock_bh(&session->frwd_lock); + sock_put(sock->sk); if (rc < 0) return rc; |