From: Alexei Potashnik Date: Tue, 21 Jul 2015 22:07:56 +0000 (-0700) Subject: target/iscsi: Fix double free of a TUR followed by a solicited NOPOUT X-Git-Tag: v3.4.111~54 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=874fc85921926885d1984c0cc6e99f569b5a450e;p=thirdparty%2Fkernel%2Fstable.git target/iscsi: Fix double free of a TUR followed by a solicited NOPOUT commit 9547308bda296b6f69876c840a0291fcfbeddbb8 upstream. Make sure all non-READ SCSI commands get targ_xfer_tag initialized to 0xffffffff, not just WRITEs. Double-free of a TUR cmd object occurs under the following scenario: 1. TUR received (targ_xfer_tag is uninitialized and left at 0) 2. TUR status sent 3. First unsolicited NOPIN is sent to initiator (gets targ_xfer_tag of 0) 4. NOPOUT for NOPIN (with TTT=0) arrives - its ExpStatSN acks TUR status, TUR is queued for removal - LIO tries to find NOPIN with TTT=0, but finds the same TUR instead, TUR is queued for removal for the 2nd time (Drop unbalanced conditional bracket usage - nab) Signed-off-by: Alexei Potashnik Signed-off-by: Spencer Baugh Signed-off-by: Nicholas Bellinger [lizf: Backported to 3.4: - adjust context - leave the braces as it is] Signed-off-by: Zefan Li --- diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c index 79665f3758ea2..963f383129273 100644 --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -981,7 +981,7 @@ done: if (cmd->targ_xfer_tag == 0xFFFFFFFF) cmd->targ_xfer_tag = conn->sess->targ_xfer_tag++; spin_unlock_bh(&conn->sess->ttt_lock); - } else if (hdr->flags & ISCSI_FLAG_CMD_WRITE) + } else cmd->targ_xfer_tag = 0xFFFFFFFF; cmd->cmd_sn = hdr->cmdsn; cmd->exp_stat_sn = hdr->exp_statsn;