6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jérémy Jean [ Upstream commit 53f6efe00cea0c0cf7bd99debe3cdac8567170b5 ] A REPLY AUTH_SEND command can derive a dhchap_skey key while a concurrent AUTH_RECEIVE command observing this REPLY state executes the failure path and frees that key. The REPLY command then continues and writes into freed memory, causing a use-after-free. KASAN reports it as: BUG: KASAN: slab-use-after-free in __sha256_final Write of size 4 at addr ffff88800359c540 ... nvmet_auth_sq_free (drivers/nvme/target/auth.c:237) nvmet_execute_auth_receive (drivers/nvme/target/fabrics-cmd-auth.c:621) Add a mutex to each submission queue to serialize authentication commands and timeout handling. Unlock the mutex before completing requests and ignore outdated timeout callbacks. Limit timeout delays to prevent immediate expiry on 32-bit kernels. Fixes: 7a277c37d352 ("nvmet-auth: Diffie-Hellman key exchange support") Cc: stable@vger.kernel.org Assisted-by: LLM Reviewed-by: Christoph Hellwig Signed-off-by: Jérémy Jean Signed-off-by: Keith Busch Signed-off-by: Sasha Levin --- drivers/nvme/target/auth.c | 1 + drivers/nvme/target/fabrics-cmd-auth.c | 32 ++++++++++++++++++++++---- drivers/nvme/target/nvmet.h | 2 ++ 3 files changed, 31 insertions(+), 4 deletions(-) diff --git a/drivers/nvme/target/auth.c b/drivers/nvme/target/auth.c index 8230a0563616b..4c68225411be3 100644 --- a/drivers/nvme/target/auth.c +++ b/drivers/nvme/target/auth.c @@ -238,6 +238,7 @@ u8 nvmet_setup_auth(struct nvmet_ctrl *ctrl, struct nvmet_sq *sq, bool reset) void nvmet_auth_sq_free(struct nvmet_sq *sq) { + sq->auth_expiry_active = false; cancel_delayed_work(&sq->auth_expired_work); #ifdef CONFIG_NVME_TARGET_TCP_TLS sq->tls_key = NULL; diff --git a/drivers/nvme/target/fabrics-cmd-auth.c b/drivers/nvme/target/fabrics-cmd-auth.c index af712c6624b36..20a2dfcbbc57f 100644 --- a/drivers/nvme/target/fabrics-cmd-auth.c +++ b/drivers/nvme/target/fabrics-cmd-auth.c @@ -6,6 +6,7 @@ */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include +#include #include #include #include @@ -18,16 +19,27 @@ static void nvmet_auth_expired_work(struct work_struct *work) struct nvmet_sq *sq = container_of(to_delayed_work(work), struct nvmet_sq, auth_expired_work); + mutex_lock(&sq->auth_lock); + /* A command may have cancelled or rearmed this timeout. */ + if (!sq->auth_expiry_active || + delayed_work_pending(&sq->auth_expired_work)) + goto out_unlock; + sq->auth_expiry_active = false; + pr_debug("%s: ctrl %d qid %d transaction %u expired, resetting\n", __func__, sq->ctrl->cntlid, sq->qid, sq->dhchap_tid); sq->dhchap_step = NVME_AUTH_DHCHAP_MESSAGE_NEGOTIATE; sq->dhchap_tid = -1; +out_unlock: + mutex_unlock(&sq->auth_lock); } void nvmet_auth_sq_init(struct nvmet_sq *sq) { /* Initialize in-band authentication */ + mutex_init(&sq->auth_lock); INIT_DELAYED_WORK(&sq->auth_expired_work, nvmet_auth_expired_work); + sq->auth_expiry_active = false; sq->authenticated = false; sq->dhchap_step = NVME_AUTH_DHCHAP_MESSAGE_NEGOTIATE; } @@ -258,6 +270,8 @@ void nvmet_execute_auth_send(struct nvmet_req *req) u16 status = 0; u8 dhchap_status; + mutex_lock(&req->sq->auth_lock); + if (req->cmd->auth_send.secp != NVME_AUTH_DHCHAP_PROTOCOL_IDENTIFIER) { status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR; req->error_loc = @@ -283,8 +297,10 @@ void nvmet_execute_auth_send(struct nvmet_req *req) offsetof(struct nvmf_auth_send_command, tl); goto done; } - if (!nvmet_check_transfer_len(req, tl)) { + if (unlikely(tl != req->transfer_len)) { pr_debug("%s: transfer length mismatch (%u)\n", __func__, tl); + mutex_unlock(&req->sq->auth_lock); + nvmet_check_transfer_len(req, tl); return; } @@ -408,10 +424,12 @@ void nvmet_execute_auth_send(struct nvmet_req *req) status, req->error_loc); if (req->sq->dhchap_step != NVME_AUTH_DHCHAP_MESSAGE_SUCCESS2 && req->sq->dhchap_step != NVME_AUTH_DHCHAP_MESSAGE_FAILURE2) { - unsigned long auth_expire_secs = ctrl->kato ? ctrl->kato : 120; + unsigned long auth_expire = min_t(u64, MAX_JIFFY_OFFSET, + (u64)(ctrl->kato ? ctrl->kato : 120) * HZ); + req->sq->auth_expiry_active = true; mod_delayed_work(system_percpu_wq, &req->sq->auth_expired_work, - auth_expire_secs * HZ); + auth_expire); goto complete; } /* Final states, clear up variables */ @@ -420,6 +438,7 @@ void nvmet_execute_auth_send(struct nvmet_req *req) nvmet_ctrl_fatal_error(ctrl); complete: + mutex_unlock(&req->sq->auth_lock); nvmet_req_complete(req, status); } @@ -538,6 +557,8 @@ void nvmet_execute_auth_receive(struct nvmet_req *req) u32 al; u16 status = 0; + mutex_lock(&req->sq->auth_lock); + if (req->cmd->auth_receive.secp != NVME_AUTH_DHCHAP_PROTOCOL_IDENTIFIER) { status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR; req->error_loc = @@ -563,8 +584,10 @@ void nvmet_execute_auth_receive(struct nvmet_req *req) offsetof(struct nvmf_auth_receive_command, al); goto done; } - if (!nvmet_check_transfer_len(req, al)) { + if (unlikely(al != req->transfer_len)) { pr_debug("%s: transfer length mismatch (%u)\n", __func__, al); + mutex_unlock(&req->sq->auth_lock); + nvmet_check_transfer_len(req, al); return; } @@ -623,5 +646,6 @@ void nvmet_execute_auth_receive(struct nvmet_req *req) nvmet_auth_sq_free(req->sq); nvmet_ctrl_fatal_error(ctrl); } + mutex_unlock(&req->sq->auth_lock); nvmet_req_complete(req, status); } diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h index 87e2fdbd18656..45fc188412d28 100644 --- a/drivers/nvme/target/nvmet.h +++ b/drivers/nvme/target/nvmet.h @@ -156,8 +156,10 @@ struct nvmet_sq { u32 sqhd; bool sqhd_disabled; #ifdef CONFIG_NVME_TARGET_AUTH + struct mutex auth_lock; bool authenticated; struct delayed_work auth_expired_work; + bool auth_expiry_active; u16 dhchap_tid; u8 sc_c; u8 dhchap_status; -- 2.53.0