| From | lizf@kernel ... | Subject | [PATCH 3.4 054/107] target/iscsi: Fix double free of a TUR followed by a solicited NOPOUT | Date | Wed, 16 Mar 2016 16:05:48 +0800 |
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From: Alexei Potashnik <alexei@purestorage.com>
3.4.111-rc1 review patch. If anyone has any objections, please let me know.
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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 <alexei@purestorage.com> Signed-off-by: Spencer Baugh <sbaugh@catern.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> [lizf: Backported to 3.4: - adjust context - leave the braces as it is] Signed-off-by: Zefan Li <lizefan@huawei.com> --- drivers/target/iscsi/iscsi_target.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c index 79665f3..963f383 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; -- 1.9.1
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