- Linux-stable-mirror - lists.linaro.org

[PATCH] serial: imx: Update mctrl old_status on RTSD interrupt

by Marek Vasut

When sending data using DMA at high baudrate (4 Mbdps in local test case) to a device with small RX buffer which keeps asserting RTS after every received byte, it is possible that the iMX UART driver would not recognize the falling edge of RTS input signal and get stuck, unable to transmit any more data. This condition happens when the following sequence of events occur: - imx_uart_mctrl_check() is called at some point and takes a snapshot of UART control signal status into sport->old_status using imx_uart_get_hwmctrl(). The RTSS/TIOCM_CTS bit is of interest here (*). - DMA transfer occurs, the remote device asserts RTS signal after each byte. The i.MX UART driver recognizes each such RTS signal change, raises an interrupt with USR1 register RTSD bit set, which leads to invocation of __imx_uart_rtsint(), which calls uart_handle_cts_change(). - If the RTS signal is deasserted, uart_handle_cts_change() clears port->hw_stopped and unblocks the port for further data transfers. - If the RTS is asserted, uart_handle_cts_change() sets port->hw_stopped and blocks the port for further data transfers. This may occur as the last interrupt of a transfer, which means port->hw_stopped remains set and the port remains blocked (**). - Any further data transfer attempts will trigger imx_uart_mctrl_check(), which will read current status of UART control signals by calling imx_uart_get_hwmctrl() (***) and compare it with sport->old_status . - If current status differs from sport->old_status for RTS signal, uart_handle_cts_change() is called and possibly unblocks the port by clearing port->hw_stopped . - If current status does not differ from sport->old_status for RTS signal, no action occurs. This may occur in case prior snapshot (*) was taken before any transfer so the RTS is deasserted, current snapshot (***) was taken after a transfer and therefore RTS is deasserted again, which means current status and sport->old_status are identical. In case (**) triggered when RTS got asserted, and made port->hw_stopped set, the port->hw_stopped will remain set because no change on RTS line is recognized by this driver and uart_handle_cts_change() is not called from here to unblock the port->hw_stopped. Update sport->old_status in __imx_uart_rtsint() accordingly to make imx_uart_mctrl_check() detect such RTS change. Note that TIOCM_CAR and TIOCM_RI bits in sport->old_status do not suffer from this problem. Fixes: ceca629e0b48 ("[ARM] 2971/1: i.MX uart handle rts irq") Signed-off-by: Marek Vasut <marex(a)denx.de> --- Cc: "Uwe Kleine-König" <u.kleine-koenig(a)pengutronix.de> Cc: Christoph Niedermaier <cniedermaier(a)dh-electronics.com> Cc: Christophe JAILLET <christophe.jaillet(a)wanadoo.fr> Cc: Esben Haabendal <esben(a)geanix.com> Cc: Fabio Estevam <festevam(a)gmail.com> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: Jiri Slaby <jirislaby(a)kernel.org> Cc: Lino Sanfilippo <l.sanfilippo(a)kunbus.com> Cc: Pengutronix Kernel Team <kernel(a)pengutronix.de> Cc: Rasmus Villemoes <linux(a)rasmusvillemoes.dk> Cc: Rickard x Andersson <rickaran(a)axis.com> Cc: Sascha Hauer <s.hauer(a)pengutronix.de> Cc: Shawn Guo <shawnguo(a)kernel.org> Cc: Stefan Eichenberger <stefan.eichenberger(a)toradex.com> Cc: imx(a)lists.linux.dev Cc: linux-arm-kernel(a)lists.infradead.org Cc: linux-serial(a)vger.kernel.org Cc: stable(a)vger.kernel.org --- drivers/tty/serial/imx.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 67d4a72eda770..3ad7f42790ef9 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -762,6 +762,10 @@ static irqreturn_t __imx_uart_rtsint(int irq, void *dev_id) imx_uart_writel(sport, USR1_RTSD, USR1); usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS; + if (usr1 & USR1_RTSS) + sport->old_status |= TIOCM_CTS; + else + sport->old_status &= ~TIOCM_CTS; uart_handle_cts_change(&sport->port, usr1); wake_up_interruptible(&sport->port.state->port.delta_msr_wait); -- 2.45.2

9 months

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FAILED: patch "[PATCH] block, bfq: fix procress reference leakage for bfqq in merge" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x 73aeab373557fa6ee4ae0b742c6211ccd9859280 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100234-dizzy-backlands-30eb@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^.. Possible dependencies: 73aeab373557 ("block, bfq: fix procress reference leakage for bfqq in merge chain") 9778369a2d6c ("block, bfq: split sync bfq_queues on a per-actuator basis") 246cf66e300b ("block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq") 337366e02b37 ("block, bfq: replace 0/1 with false/true in bic apis") 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'") dc469ba2e790 ("block/bfq: Use the new blk_opf_t type") 4e54a2493e58 ("bfq: Get rid of __bio_blkcg() usage") 09f871868080 ("bfq: Track whether bfq_group is still online") ea591cd4eb27 ("bfq: Update cgroup information before merging bio") 3bc5e683c67d ("bfq: Split shared queues on move between cgroups") f6bad159f5d5 ("block/bfq-iosched.c: use "false" rather than "BLK_RW_ASYNC"") a0725c22cd84 ("bfq: use bfq_bic_lookup in bfq_limit_depth") 1f18b7005b49 ("bfq: Limit waker detection in time") 76f1df88bbc2 ("bfq: Limit number of requests consumed by each cgroup") 44dfa279f117 ("bfq: Store full bitmap depth in bfq_data") ae0f1a732f4a ("blk-mq: Stop using pointers for blk_mq_tags bitmap tags") e155b0c238b2 ("blk-mq: Use shared tags for shared sbitmap support") 645db34e5050 ("blk-mq: Refactor and rename blk_mq_free_map_and_{requests->rqs}()") 63064be150e4 ("blk-mq: Add blk_mq_alloc_map_and_rqs()") a7e7388dced4 ("blk-mq: Add blk_mq_tag_update_sched_shared_sbitmap()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 73aeab373557fa6ee4ae0b742c6211ccd9859280 Mon Sep 17 00:00:00 2001 From: Yu Kuai <yukuai3(a)huawei.com> Date: Mon, 9 Sep 2024 21:41:49 +0800 Subject: [PATCH] block, bfq: fix procress reference leakage for bfqq in merge chain MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Original state: Process 1 Process 2 Process 3 Process 4 (BIC1) (BIC2) (BIC3) (BIC4) Λ | | | \--------------\ \-------------\ \-------------\| V V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 1 2 4 After commit 0e456dba86c7 ("block, bfq: choose the last bfqq from merge chain in bfq_setup_cooperator()"), if P1 issues a new IO: Without the patch: Process 1 Process 2 Process 3 Process 4 (BIC1) (BIC2) (BIC3) (BIC4) Λ | | | \------------------------------\ \-------------\| V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 0 2 4 bfqq3 will be used to handle IO from P1, this is not expected, IO should be redirected to bfqq4; With the patch: ------------------------------------------- | | Process 1 Process 2 Process 3 | Process 4 (BIC1) (BIC2) (BIC3) | (BIC4) | | | | \-------------\ \-------------\| V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 0 2 4 IO is redirected to bfqq4, however, procress reference of bfqq3 is still 2, while there is only P2 using it. Fix the problem by calling bfq_merge_bfqqs() for each bfqq in the merge chain. Also change bfqq_merge_bfqqs() to return new_bfqq to simplify code. Fixes: 0e456dba86c7 ("block, bfq: choose the last bfqq from merge chain in bfq_setup_cooperator()") Signed-off-by: Yu Kuai <yukuai3(a)huawei.com> Link: https://lore.kernel.org/r/20240909134154.954924-3-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index d5d39974c674..f4192d5411d2 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -3129,10 +3129,12 @@ void bfq_release_process_ref(struct bfq_data *bfqd, struct bfq_queue *bfqq) bfq_put_queue(bfqq); } -static void -bfq_merge_bfqqs(struct bfq_data *bfqd, struct bfq_io_cq *bic, - struct bfq_queue *bfqq, struct bfq_queue *new_bfqq) +static struct bfq_queue *bfq_merge_bfqqs(struct bfq_data *bfqd, + struct bfq_io_cq *bic, + struct bfq_queue *bfqq) { + struct bfq_queue *new_bfqq = bfqq->new_bfqq; + bfq_log_bfqq(bfqd, bfqq, "merging with queue %lu", (unsigned long)new_bfqq->pid); /* Save weight raising and idle window of the merged queues */ @@ -3226,6 +3228,8 @@ bfq_merge_bfqqs(struct bfq_data *bfqd, struct bfq_io_cq *bic, bfq_reassign_last_bfqq(bfqq, new_bfqq); bfq_release_process_ref(bfqd, bfqq); + + return new_bfqq; } static bool bfq_allow_bio_merge(struct request_queue *q, struct request *rq, @@ -3261,14 +3265,8 @@ static bool bfq_allow_bio_merge(struct request_queue *q, struct request *rq, * fulfilled, i.e., bic can be redirected to new_bfqq * and bfqq can be put. */ - bfq_merge_bfqqs(bfqd, bfqd->bio_bic, bfqq, - new_bfqq); - /* - * If we get here, bio will be queued into new_queue, - * so use new_bfqq to decide whether bio and rq can be - * merged. - */ - bfqq = new_bfqq; + while (bfqq != new_bfqq) + bfqq = bfq_merge_bfqqs(bfqd, bfqd->bio_bic, bfqq); /* * Change also bqfd->bio_bfqq, as @@ -5705,9 +5703,7 @@ bfq_do_early_stable_merge(struct bfq_data *bfqd, struct bfq_queue *bfqq, * state before killing it. */ bfqq->bic = bic; - bfq_merge_bfqqs(bfqd, bic, bfqq, new_bfqq); - - return new_bfqq; + return bfq_merge_bfqqs(bfqd, bic, bfqq); } /* @@ -6162,6 +6158,7 @@ static bool __bfq_insert_request(struct bfq_data *bfqd, struct request *rq) bool waiting, idle_timer_disabled = false; if (new_bfqq) { + struct bfq_queue *old_bfqq = bfqq; /* * Release the request's reference to the old bfqq * and make sure one is taken to the shared queue. @@ -6178,18 +6175,18 @@ static bool __bfq_insert_request(struct bfq_data *bfqd, struct request *rq) * new_bfqq. */ if (bic_to_bfqq(RQ_BIC(rq), true, - bfq_actuator_index(bfqd, rq->bio)) == bfqq) - bfq_merge_bfqqs(bfqd, RQ_BIC(rq), - bfqq, new_bfqq); + bfq_actuator_index(bfqd, rq->bio)) == bfqq) { + while (bfqq != new_bfqq) + bfqq = bfq_merge_bfqqs(bfqd, RQ_BIC(rq), bfqq); + } - bfq_clear_bfqq_just_created(bfqq); + bfq_clear_bfqq_just_created(old_bfqq); /* * rq is about to be enqueued into new_bfqq, * release rq reference on bfqq */ - bfq_put_queue(bfqq); + bfq_put_queue(old_bfqq); rq->elv.priv[1] = new_bfqq; - bfqq = new_bfqq; } bfq_update_io_thinktime(bfqd, bfqq);

9 months

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FAILED: patch "[PATCH] block, bfq: fix procress reference leakage for bfqq in merge" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 73aeab373557fa6ee4ae0b742c6211ccd9859280 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100232-unheated-trailing-4528@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: 73aeab373557 ("block, bfq: fix procress reference leakage for bfqq in merge chain") 9778369a2d6c ("block, bfq: split sync bfq_queues on a per-actuator basis") 246cf66e300b ("block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq") 337366e02b37 ("block, bfq: replace 0/1 with false/true in bic apis") 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'") dc469ba2e790 ("block/bfq: Use the new blk_opf_t type") 4e54a2493e58 ("bfq: Get rid of __bio_blkcg() usage") 09f871868080 ("bfq: Track whether bfq_group is still online") ea591cd4eb27 ("bfq: Update cgroup information before merging bio") 3bc5e683c67d ("bfq: Split shared queues on move between cgroups") f6bad159f5d5 ("block/bfq-iosched.c: use "false" rather than "BLK_RW_ASYNC"") a0725c22cd84 ("bfq: use bfq_bic_lookup in bfq_limit_depth") 1f18b7005b49 ("bfq: Limit waker detection in time") 76f1df88bbc2 ("bfq: Limit number of requests consumed by each cgroup") 44dfa279f117 ("bfq: Store full bitmap depth in bfq_data") ae0f1a732f4a ("blk-mq: Stop using pointers for blk_mq_tags bitmap tags") e155b0c238b2 ("blk-mq: Use shared tags for shared sbitmap support") 645db34e5050 ("blk-mq: Refactor and rename blk_mq_free_map_and_{requests->rqs}()") 63064be150e4 ("blk-mq: Add blk_mq_alloc_map_and_rqs()") a7e7388dced4 ("blk-mq: Add blk_mq_tag_update_sched_shared_sbitmap()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 73aeab373557fa6ee4ae0b742c6211ccd9859280 Mon Sep 17 00:00:00 2001 From: Yu Kuai <yukuai3(a)huawei.com> Date: Mon, 9 Sep 2024 21:41:49 +0800 Subject: [PATCH] block, bfq: fix procress reference leakage for bfqq in merge chain MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Original state: Process 1 Process 2 Process 3 Process 4 (BIC1) (BIC2) (BIC3) (BIC4) Λ | | | \--------------\ \-------------\ \-------------\| V V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 1 2 4 After commit 0e456dba86c7 ("block, bfq: choose the last bfqq from merge chain in bfq_setup_cooperator()"), if P1 issues a new IO: Without the patch: Process 1 Process 2 Process 3 Process 4 (BIC1) (BIC2) (BIC3) (BIC4) Λ | | | \------------------------------\ \-------------\| V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 0 2 4 bfqq3 will be used to handle IO from P1, this is not expected, IO should be redirected to bfqq4; With the patch: ------------------------------------------- | | Process 1 Process 2 Process 3 | Process 4 (BIC1) (BIC2) (BIC3) | (BIC4) | | | | \-------------\ \-------------\| V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 0 2 4 IO is redirected to bfqq4, however, procress reference of bfqq3 is still 2, while there is only P2 using it. Fix the problem by calling bfq_merge_bfqqs() for each bfqq in the merge chain. Also change bfqq_merge_bfqqs() to return new_bfqq to simplify code. Fixes: 0e456dba86c7 ("block, bfq: choose the last bfqq from merge chain in bfq_setup_cooperator()") Signed-off-by: Yu Kuai <yukuai3(a)huawei.com> Link: https://lore.kernel.org/r/20240909134154.954924-3-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index d5d39974c674..f4192d5411d2 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -3129,10 +3129,12 @@ void bfq_release_process_ref(struct bfq_data *bfqd, struct bfq_queue *bfqq) bfq_put_queue(bfqq); } -static void -bfq_merge_bfqqs(struct bfq_data *bfqd, struct bfq_io_cq *bic, - struct bfq_queue *bfqq, struct bfq_queue *new_bfqq) +static struct bfq_queue *bfq_merge_bfqqs(struct bfq_data *bfqd, + struct bfq_io_cq *bic, + struct bfq_queue *bfqq) { + struct bfq_queue *new_bfqq = bfqq->new_bfqq; + bfq_log_bfqq(bfqd, bfqq, "merging with queue %lu", (unsigned long)new_bfqq->pid); /* Save weight raising and idle window of the merged queues */ @@ -3226,6 +3228,8 @@ bfq_merge_bfqqs(struct bfq_data *bfqd, struct bfq_io_cq *bic, bfq_reassign_last_bfqq(bfqq, new_bfqq); bfq_release_process_ref(bfqd, bfqq); + + return new_bfqq; } static bool bfq_allow_bio_merge(struct request_queue *q, struct request *rq, @@ -3261,14 +3265,8 @@ static bool bfq_allow_bio_merge(struct request_queue *q, struct request *rq, * fulfilled, i.e., bic can be redirected to new_bfqq * and bfqq can be put. */ - bfq_merge_bfqqs(bfqd, bfqd->bio_bic, bfqq, - new_bfqq); - /* - * If we get here, bio will be queued into new_queue, - * so use new_bfqq to decide whether bio and rq can be - * merged. - */ - bfqq = new_bfqq; + while (bfqq != new_bfqq) + bfqq = bfq_merge_bfqqs(bfqd, bfqd->bio_bic, bfqq); /* * Change also bqfd->bio_bfqq, as @@ -5705,9 +5703,7 @@ bfq_do_early_stable_merge(struct bfq_data *bfqd, struct bfq_queue *bfqq, * state before killing it. */ bfqq->bic = bic; - bfq_merge_bfqqs(bfqd, bic, bfqq, new_bfqq); - - return new_bfqq; + return bfq_merge_bfqqs(bfqd, bic, bfqq); } /* @@ -6162,6 +6158,7 @@ static bool __bfq_insert_request(struct bfq_data *bfqd, struct request *rq) bool waiting, idle_timer_disabled = false; if (new_bfqq) { + struct bfq_queue *old_bfqq = bfqq; /* * Release the request's reference to the old bfqq * and make sure one is taken to the shared queue. @@ -6178,18 +6175,18 @@ static bool __bfq_insert_request(struct bfq_data *bfqd, struct request *rq) * new_bfqq. */ if (bic_to_bfqq(RQ_BIC(rq), true, - bfq_actuator_index(bfqd, rq->bio)) == bfqq) - bfq_merge_bfqqs(bfqd, RQ_BIC(rq), - bfqq, new_bfqq); + bfq_actuator_index(bfqd, rq->bio)) == bfqq) { + while (bfqq != new_bfqq) + bfqq = bfq_merge_bfqqs(bfqd, RQ_BIC(rq), bfqq); + } - bfq_clear_bfqq_just_created(bfqq); + bfq_clear_bfqq_just_created(old_bfqq); /* * rq is about to be enqueued into new_bfqq, * release rq reference on bfqq */ - bfq_put_queue(bfqq); + bfq_put_queue(old_bfqq); rq->elv.priv[1] = new_bfqq; - bfqq = new_bfqq; } bfq_update_io_thinktime(bfqd, bfqq);

9 months

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FAILED: patch "[PATCH] block, bfq: fix procress reference leakage for bfqq in merge" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 73aeab373557fa6ee4ae0b742c6211ccd9859280 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100231-difficult-nail-04b1@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: 73aeab373557 ("block, bfq: fix procress reference leakage for bfqq in merge chain") 9778369a2d6c ("block, bfq: split sync bfq_queues on a per-actuator basis") 246cf66e300b ("block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq") 337366e02b37 ("block, bfq: replace 0/1 with false/true in bic apis") 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'") dc469ba2e790 ("block/bfq: Use the new blk_opf_t type") 4e54a2493e58 ("bfq: Get rid of __bio_blkcg() usage") 09f871868080 ("bfq: Track whether bfq_group is still online") ea591cd4eb27 ("bfq: Update cgroup information before merging bio") 3bc5e683c67d ("bfq: Split shared queues on move between cgroups") f6bad159f5d5 ("block/bfq-iosched.c: use "false" rather than "BLK_RW_ASYNC"") a0725c22cd84 ("bfq: use bfq_bic_lookup in bfq_limit_depth") 1f18b7005b49 ("bfq: Limit waker detection in time") 76f1df88bbc2 ("bfq: Limit number of requests consumed by each cgroup") 44dfa279f117 ("bfq: Store full bitmap depth in bfq_data") ae0f1a732f4a ("blk-mq: Stop using pointers for blk_mq_tags bitmap tags") e155b0c238b2 ("blk-mq: Use shared tags for shared sbitmap support") 645db34e5050 ("blk-mq: Refactor and rename blk_mq_free_map_and_{requests->rqs}()") 63064be150e4 ("blk-mq: Add blk_mq_alloc_map_and_rqs()") a7e7388dced4 ("blk-mq: Add blk_mq_tag_update_sched_shared_sbitmap()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 73aeab373557fa6ee4ae0b742c6211ccd9859280 Mon Sep 17 00:00:00 2001 From: Yu Kuai <yukuai3(a)huawei.com> Date: Mon, 9 Sep 2024 21:41:49 +0800 Subject: [PATCH] block, bfq: fix procress reference leakage for bfqq in merge chain MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Original state: Process 1 Process 2 Process 3 Process 4 (BIC1) (BIC2) (BIC3) (BIC4) Λ | | | \--------------\ \-------------\ \-------------\| V V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 1 2 4 After commit 0e456dba86c7 ("block, bfq: choose the last bfqq from merge chain in bfq_setup_cooperator()"), if P1 issues a new IO: Without the patch: Process 1 Process 2 Process 3 Process 4 (BIC1) (BIC2) (BIC3) (BIC4) Λ | | | \------------------------------\ \-------------\| V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 0 2 4 bfqq3 will be used to handle IO from P1, this is not expected, IO should be redirected to bfqq4; With the patch: ------------------------------------------- | | Process 1 Process 2 Process 3 | Process 4 (BIC1) (BIC2) (BIC3) | (BIC4) | | | | \-------------\ \-------------\| V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 0 2 4 IO is redirected to bfqq4, however, procress reference of bfqq3 is still 2, while there is only P2 using it. Fix the problem by calling bfq_merge_bfqqs() for each bfqq in the merge chain. Also change bfqq_merge_bfqqs() to return new_bfqq to simplify code. Fixes: 0e456dba86c7 ("block, bfq: choose the last bfqq from merge chain in bfq_setup_cooperator()") Signed-off-by: Yu Kuai <yukuai3(a)huawei.com> Link: https://lore.kernel.org/r/20240909134154.954924-3-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index d5d39974c674..f4192d5411d2 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -3129,10 +3129,12 @@ void bfq_release_process_ref(struct bfq_data *bfqd, struct bfq_queue *bfqq) bfq_put_queue(bfqq); } -static void -bfq_merge_bfqqs(struct bfq_data *bfqd, struct bfq_io_cq *bic, - struct bfq_queue *bfqq, struct bfq_queue *new_bfqq) +static struct bfq_queue *bfq_merge_bfqqs(struct bfq_data *bfqd, + struct bfq_io_cq *bic, + struct bfq_queue *bfqq) { + struct bfq_queue *new_bfqq = bfqq->new_bfqq; + bfq_log_bfqq(bfqd, bfqq, "merging with queue %lu", (unsigned long)new_bfqq->pid); /* Save weight raising and idle window of the merged queues */ @@ -3226,6 +3228,8 @@ bfq_merge_bfqqs(struct bfq_data *bfqd, struct bfq_io_cq *bic, bfq_reassign_last_bfqq(bfqq, new_bfqq); bfq_release_process_ref(bfqd, bfqq); + + return new_bfqq; } static bool bfq_allow_bio_merge(struct request_queue *q, struct request *rq, @@ -3261,14 +3265,8 @@ static bool bfq_allow_bio_merge(struct request_queue *q, struct request *rq, * fulfilled, i.e., bic can be redirected to new_bfqq * and bfqq can be put. */ - bfq_merge_bfqqs(bfqd, bfqd->bio_bic, bfqq, - new_bfqq); - /* - * If we get here, bio will be queued into new_queue, - * so use new_bfqq to decide whether bio and rq can be - * merged. - */ - bfqq = new_bfqq; + while (bfqq != new_bfqq) + bfqq = bfq_merge_bfqqs(bfqd, bfqd->bio_bic, bfqq); /* * Change also bqfd->bio_bfqq, as @@ -5705,9 +5703,7 @@ bfq_do_early_stable_merge(struct bfq_data *bfqd, struct bfq_queue *bfqq, * state before killing it. */ bfqq->bic = bic; - bfq_merge_bfqqs(bfqd, bic, bfqq, new_bfqq); - - return new_bfqq; + return bfq_merge_bfqqs(bfqd, bic, bfqq); } /* @@ -6162,6 +6158,7 @@ static bool __bfq_insert_request(struct bfq_data *bfqd, struct request *rq) bool waiting, idle_timer_disabled = false; if (new_bfqq) { + struct bfq_queue *old_bfqq = bfqq; /* * Release the request's reference to the old bfqq * and make sure one is taken to the shared queue. @@ -6178,18 +6175,18 @@ static bool __bfq_insert_request(struct bfq_data *bfqd, struct request *rq) * new_bfqq. */ if (bic_to_bfqq(RQ_BIC(rq), true, - bfq_actuator_index(bfqd, rq->bio)) == bfqq) - bfq_merge_bfqqs(bfqd, RQ_BIC(rq), - bfqq, new_bfqq); + bfq_actuator_index(bfqd, rq->bio)) == bfqq) { + while (bfqq != new_bfqq) + bfqq = bfq_merge_bfqqs(bfqd, RQ_BIC(rq), bfqq); + } - bfq_clear_bfqq_just_created(bfqq); + bfq_clear_bfqq_just_created(old_bfqq); /* * rq is about to be enqueued into new_bfqq, * release rq reference on bfqq */ - bfq_put_queue(bfqq); + bfq_put_queue(old_bfqq); rq->elv.priv[1] = new_bfqq; - bfqq = new_bfqq; } bfq_update_io_thinktime(bfqd, bfqq);

9 months

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FAILED: patch "[PATCH] block, bfq: fix procress reference leakage for bfqq in merge" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 73aeab373557fa6ee4ae0b742c6211ccd9859280 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100230-epilogue-hush-6a49@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: 73aeab373557 ("block, bfq: fix procress reference leakage for bfqq in merge chain") 9778369a2d6c ("block, bfq: split sync bfq_queues on a per-actuator basis") 246cf66e300b ("block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq") 337366e02b37 ("block, bfq: replace 0/1 with false/true in bic apis") 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'") dc469ba2e790 ("block/bfq: Use the new blk_opf_t type") 4e54a2493e58 ("bfq: Get rid of __bio_blkcg() usage") 09f871868080 ("bfq: Track whether bfq_group is still online") ea591cd4eb27 ("bfq: Update cgroup information before merging bio") 3bc5e683c67d ("bfq: Split shared queues on move between cgroups") f6bad159f5d5 ("block/bfq-iosched.c: use "false" rather than "BLK_RW_ASYNC"") a0725c22cd84 ("bfq: use bfq_bic_lookup in bfq_limit_depth") 1f18b7005b49 ("bfq: Limit waker detection in time") 76f1df88bbc2 ("bfq: Limit number of requests consumed by each cgroup") 44dfa279f117 ("bfq: Store full bitmap depth in bfq_data") ae0f1a732f4a ("blk-mq: Stop using pointers for blk_mq_tags bitmap tags") e155b0c238b2 ("blk-mq: Use shared tags for shared sbitmap support") 645db34e5050 ("blk-mq: Refactor and rename blk_mq_free_map_and_{requests->rqs}()") 63064be150e4 ("blk-mq: Add blk_mq_alloc_map_and_rqs()") a7e7388dced4 ("blk-mq: Add blk_mq_tag_update_sched_shared_sbitmap()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 73aeab373557fa6ee4ae0b742c6211ccd9859280 Mon Sep 17 00:00:00 2001 From: Yu Kuai <yukuai3(a)huawei.com> Date: Mon, 9 Sep 2024 21:41:49 +0800 Subject: [PATCH] block, bfq: fix procress reference leakage for bfqq in merge chain MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Original state: Process 1 Process 2 Process 3 Process 4 (BIC1) (BIC2) (BIC3) (BIC4) Λ | | | \--------------\ \-------------\ \-------------\| V V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 1 2 4 After commit 0e456dba86c7 ("block, bfq: choose the last bfqq from merge chain in bfq_setup_cooperator()"), if P1 issues a new IO: Without the patch: Process 1 Process 2 Process 3 Process 4 (BIC1) (BIC2) (BIC3) (BIC4) Λ | | | \------------------------------\ \-------------\| V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 0 2 4 bfqq3 will be used to handle IO from P1, this is not expected, IO should be redirected to bfqq4; With the patch: ------------------------------------------- | | Process 1 Process 2 Process 3 | Process 4 (BIC1) (BIC2) (BIC3) | (BIC4) | | | | \-------------\ \-------------\| V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 0 2 4 IO is redirected to bfqq4, however, procress reference of bfqq3 is still 2, while there is only P2 using it. Fix the problem by calling bfq_merge_bfqqs() for each bfqq in the merge chain. Also change bfqq_merge_bfqqs() to return new_bfqq to simplify code. Fixes: 0e456dba86c7 ("block, bfq: choose the last bfqq from merge chain in bfq_setup_cooperator()") Signed-off-by: Yu Kuai <yukuai3(a)huawei.com> Link: https://lore.kernel.org/r/20240909134154.954924-3-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index d5d39974c674..f4192d5411d2 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -3129,10 +3129,12 @@ void bfq_release_process_ref(struct bfq_data *bfqd, struct bfq_queue *bfqq) bfq_put_queue(bfqq); } -static void -bfq_merge_bfqqs(struct bfq_data *bfqd, struct bfq_io_cq *bic, - struct bfq_queue *bfqq, struct bfq_queue *new_bfqq) +static struct bfq_queue *bfq_merge_bfqqs(struct bfq_data *bfqd, + struct bfq_io_cq *bic, + struct bfq_queue *bfqq) { + struct bfq_queue *new_bfqq = bfqq->new_bfqq; + bfq_log_bfqq(bfqd, bfqq, "merging with queue %lu", (unsigned long)new_bfqq->pid); /* Save weight raising and idle window of the merged queues */ @@ -3226,6 +3228,8 @@ bfq_merge_bfqqs(struct bfq_data *bfqd, struct bfq_io_cq *bic, bfq_reassign_last_bfqq(bfqq, new_bfqq); bfq_release_process_ref(bfqd, bfqq); + + return new_bfqq; } static bool bfq_allow_bio_merge(struct request_queue *q, struct request *rq, @@ -3261,14 +3265,8 @@ static bool bfq_allow_bio_merge(struct request_queue *q, struct request *rq, * fulfilled, i.e., bic can be redirected to new_bfqq * and bfqq can be put. */ - bfq_merge_bfqqs(bfqd, bfqd->bio_bic, bfqq, - new_bfqq); - /* - * If we get here, bio will be queued into new_queue, - * so use new_bfqq to decide whether bio and rq can be - * merged. - */ - bfqq = new_bfqq; + while (bfqq != new_bfqq) + bfqq = bfq_merge_bfqqs(bfqd, bfqd->bio_bic, bfqq); /* * Change also bqfd->bio_bfqq, as @@ -5705,9 +5703,7 @@ bfq_do_early_stable_merge(struct bfq_data *bfqd, struct bfq_queue *bfqq, * state before killing it. */ bfqq->bic = bic; - bfq_merge_bfqqs(bfqd, bic, bfqq, new_bfqq); - - return new_bfqq; + return bfq_merge_bfqqs(bfqd, bic, bfqq); } /* @@ -6162,6 +6158,7 @@ static bool __bfq_insert_request(struct bfq_data *bfqd, struct request *rq) bool waiting, idle_timer_disabled = false; if (new_bfqq) { + struct bfq_queue *old_bfqq = bfqq; /* * Release the request's reference to the old bfqq * and make sure one is taken to the shared queue. @@ -6178,18 +6175,18 @@ static bool __bfq_insert_request(struct bfq_data *bfqd, struct request *rq) * new_bfqq. */ if (bic_to_bfqq(RQ_BIC(rq), true, - bfq_actuator_index(bfqd, rq->bio)) == bfqq) - bfq_merge_bfqqs(bfqd, RQ_BIC(rq), - bfqq, new_bfqq); + bfq_actuator_index(bfqd, rq->bio)) == bfqq) { + while (bfqq != new_bfqq) + bfqq = bfq_merge_bfqqs(bfqd, RQ_BIC(rq), bfqq); + } - bfq_clear_bfqq_just_created(bfqq); + bfq_clear_bfqq_just_created(old_bfqq); /* * rq is about to be enqueued into new_bfqq, * release rq reference on bfqq */ - bfq_put_queue(bfqq); + bfq_put_queue(old_bfqq); rq->elv.priv[1] = new_bfqq; - bfqq = new_bfqq; } bfq_update_io_thinktime(bfqd, bfqq);

9 months

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FAILED: patch "[PATCH] block, bfq: fix procress reference leakage for bfqq in merge" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 73aeab373557fa6ee4ae0b742c6211ccd9859280 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100229-lazy-atonable-fd03@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: 73aeab373557 ("block, bfq: fix procress reference leakage for bfqq in merge chain") 9778369a2d6c ("block, bfq: split sync bfq_queues on a per-actuator basis") 246cf66e300b ("block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq") 337366e02b37 ("block, bfq: replace 0/1 with false/true in bic apis") 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 73aeab373557fa6ee4ae0b742c6211ccd9859280 Mon Sep 17 00:00:00 2001 From: Yu Kuai <yukuai3(a)huawei.com> Date: Mon, 9 Sep 2024 21:41:49 +0800 Subject: [PATCH] block, bfq: fix procress reference leakage for bfqq in merge chain MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Original state: Process 1 Process 2 Process 3 Process 4 (BIC1) (BIC2) (BIC3) (BIC4) Λ | | | \--------------\ \-------------\ \-------------\| V V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 1 2 4 After commit 0e456dba86c7 ("block, bfq: choose the last bfqq from merge chain in bfq_setup_cooperator()"), if P1 issues a new IO: Without the patch: Process 1 Process 2 Process 3 Process 4 (BIC1) (BIC2) (BIC3) (BIC4) Λ | | | \------------------------------\ \-------------\| V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 0 2 4 bfqq3 will be used to handle IO from P1, this is not expected, IO should be redirected to bfqq4; With the patch: ------------------------------------------- | | Process 1 Process 2 Process 3 | Process 4 (BIC1) (BIC2) (BIC3) | (BIC4) | | | | \-------------\ \-------------\| V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 0 2 4 IO is redirected to bfqq4, however, procress reference of bfqq3 is still 2, while there is only P2 using it. Fix the problem by calling bfq_merge_bfqqs() for each bfqq in the merge chain. Also change bfqq_merge_bfqqs() to return new_bfqq to simplify code. Fixes: 0e456dba86c7 ("block, bfq: choose the last bfqq from merge chain in bfq_setup_cooperator()") Signed-off-by: Yu Kuai <yukuai3(a)huawei.com> Link: https://lore.kernel.org/r/20240909134154.954924-3-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index d5d39974c674..f4192d5411d2 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -3129,10 +3129,12 @@ void bfq_release_process_ref(struct bfq_data *bfqd, struct bfq_queue *bfqq) bfq_put_queue(bfqq); } -static void -bfq_merge_bfqqs(struct bfq_data *bfqd, struct bfq_io_cq *bic, - struct bfq_queue *bfqq, struct bfq_queue *new_bfqq) +static struct bfq_queue *bfq_merge_bfqqs(struct bfq_data *bfqd, + struct bfq_io_cq *bic, + struct bfq_queue *bfqq) { + struct bfq_queue *new_bfqq = bfqq->new_bfqq; + bfq_log_bfqq(bfqd, bfqq, "merging with queue %lu", (unsigned long)new_bfqq->pid); /* Save weight raising and idle window of the merged queues */ @@ -3226,6 +3228,8 @@ bfq_merge_bfqqs(struct bfq_data *bfqd, struct bfq_io_cq *bic, bfq_reassign_last_bfqq(bfqq, new_bfqq); bfq_release_process_ref(bfqd, bfqq); + + return new_bfqq; } static bool bfq_allow_bio_merge(struct request_queue *q, struct request *rq, @@ -3261,14 +3265,8 @@ static bool bfq_allow_bio_merge(struct request_queue *q, struct request *rq, * fulfilled, i.e., bic can be redirected to new_bfqq * and bfqq can be put. */ - bfq_merge_bfqqs(bfqd, bfqd->bio_bic, bfqq, - new_bfqq); - /* - * If we get here, bio will be queued into new_queue, - * so use new_bfqq to decide whether bio and rq can be - * merged. - */ - bfqq = new_bfqq; + while (bfqq != new_bfqq) + bfqq = bfq_merge_bfqqs(bfqd, bfqd->bio_bic, bfqq); /* * Change also bqfd->bio_bfqq, as @@ -5705,9 +5703,7 @@ bfq_do_early_stable_merge(struct bfq_data *bfqd, struct bfq_queue *bfqq, * state before killing it. */ bfqq->bic = bic; - bfq_merge_bfqqs(bfqd, bic, bfqq, new_bfqq); - - return new_bfqq; + return bfq_merge_bfqqs(bfqd, bic, bfqq); } /* @@ -6162,6 +6158,7 @@ static bool __bfq_insert_request(struct bfq_data *bfqd, struct request *rq) bool waiting, idle_timer_disabled = false; if (new_bfqq) { + struct bfq_queue *old_bfqq = bfqq; /* * Release the request's reference to the old bfqq * and make sure one is taken to the shared queue. @@ -6178,18 +6175,18 @@ static bool __bfq_insert_request(struct bfq_data *bfqd, struct request *rq) * new_bfqq. */ if (bic_to_bfqq(RQ_BIC(rq), true, - bfq_actuator_index(bfqd, rq->bio)) == bfqq) - bfq_merge_bfqqs(bfqd, RQ_BIC(rq), - bfqq, new_bfqq); + bfq_actuator_index(bfqd, rq->bio)) == bfqq) { + while (bfqq != new_bfqq) + bfqq = bfq_merge_bfqqs(bfqd, RQ_BIC(rq), bfqq); + } - bfq_clear_bfqq_just_created(bfqq); + bfq_clear_bfqq_just_created(old_bfqq); /* * rq is about to be enqueued into new_bfqq, * release rq reference on bfqq */ - bfq_put_queue(bfqq); + bfq_put_queue(old_bfqq); rq->elv.priv[1] = new_bfqq; - bfqq = new_bfqq; } bfq_update_io_thinktime(bfqd, bfqq);

9 months

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FAILED: patch "[PATCH] block, bfq: fix uaf for accessing waker_bfqq after splitting" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x 1ba0403ac6447f2d63914fb760c44a3b19c44eaf # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100223-gutter-exchange-0c2b@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^.. Possible dependencies: 1ba0403ac644 ("block, bfq: fix uaf for accessing waker_bfqq after splitting") fd571df0ac5b ("block, bfq: turn bfqq_data into an array in bfq_io_cq") a61230470c8c ("block, bfq: move io_cq-persistent bfqq data into a dedicated struct") 9778369a2d6c ("block, bfq: split sync bfq_queues on a per-actuator basis") 246cf66e300b ("block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq") 337366e02b37 ("block, bfq: replace 0/1 with false/true in bic apis") 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'") a1795c2ccb1e ("bfq: fix waker_bfqq inconsistency crash") dc469ba2e790 ("block/bfq: Use the new blk_opf_t type") f950667356ce ("bfq: Relax waker detection for shared queues") 4e54a2493e58 ("bfq: Get rid of __bio_blkcg() usage") 09f871868080 ("bfq: Track whether bfq_group is still online") ea591cd4eb27 ("bfq: Update cgroup information before merging bio") 3bc5e683c67d ("bfq: Split shared queues on move between cgroups") 70456e5210f4 ("bfq: Avoid false marking of bic as stably merged") f6bad159f5d5 ("block/bfq-iosched.c: use "false" rather than "BLK_RW_ASYNC"") a0725c22cd84 ("bfq: use bfq_bic_lookup in bfq_limit_depth") 1f18b7005b49 ("bfq: Limit waker detection in time") 76f1df88bbc2 ("bfq: Limit number of requests consumed by each cgroup") 44dfa279f117 ("bfq: Store full bitmap depth in bfq_data") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 1ba0403ac6447f2d63914fb760c44a3b19c44eaf Mon Sep 17 00:00:00 2001 From: Yu Kuai <yukuai3(a)huawei.com> Date: Mon, 9 Sep 2024 21:41:48 +0800 Subject: [PATCH] block, bfq: fix uaf for accessing waker_bfqq after splitting After commit 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()"), if the current procress is the last holder of bfqq, the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq may in the merge chain of bfqq, hence just recored waker_bfqq is still not safe. Fix the problem by adding a helper bfq_waker_bfqq() to check if bfqq->waker_bfqq is in the merge chain, and current procress is the only holder. Fixes: 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()") Signed-off-by: Yu Kuai <yukuai3(a)huawei.com> Link: https://lore.kernel.org/r/20240909134154.954924-2-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index d1bf2b8a3576..d5d39974c674 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -6825,6 +6825,31 @@ static void bfq_prepare_request(struct request *rq) rq->elv.priv[0] = rq->elv.priv[1] = NULL; } +static struct bfq_queue *bfq_waker_bfqq(struct bfq_queue *bfqq) +{ + struct bfq_queue *new_bfqq = bfqq->new_bfqq; + struct bfq_queue *waker_bfqq = bfqq->waker_bfqq; + + if (!waker_bfqq) + return NULL; + + while (new_bfqq) { + if (new_bfqq == waker_bfqq) { + /* + * If waker_bfqq is in the merge chain, and current + * is the only procress. + */ + if (bfqq_process_refs(waker_bfqq) == 1) + return NULL; + break; + } + + new_bfqq = new_bfqq->new_bfqq; + } + + return waker_bfqq; +} + /* * If needed, init rq, allocate bfq data structures associated with * rq, and increment reference counters in the destination bfq_queue @@ -6886,7 +6911,7 @@ static struct bfq_queue *bfq_init_rq(struct request *rq) /* If the queue was seeky for too long, break it apart. */ if (bfq_bfqq_coop(bfqq) && bfq_bfqq_split_coop(bfqq) && !bic->bfqq_data[a_idx].stably_merged) { - struct bfq_queue *old_bfqq = bfqq; + struct bfq_queue *waker_bfqq = bfq_waker_bfqq(bfqq); /* Update bic before losing reference to bfqq */ if (bfq_bfqq_in_large_burst(bfqq)) @@ -6906,7 +6931,7 @@ static struct bfq_queue *bfq_init_rq(struct request *rq) bfqq_already_existing = true; if (!bfqq_already_existing) { - bfqq->waker_bfqq = old_bfqq->waker_bfqq; + bfqq->waker_bfqq = waker_bfqq; bfqq->tentative_waker_bfqq = NULL; /* @@ -6916,7 +6941,7 @@ static struct bfq_queue *bfq_init_rq(struct request *rq) * woken_list of the waker. See * bfq_check_waker for details. */ - if (bfqq->waker_bfqq) + if (waker_bfqq) hlist_add_head(&bfqq->woken_list_node, &bfqq->waker_bfqq->woken_list); }

9 months

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FAILED: patch "[PATCH] block, bfq: fix uaf for accessing waker_bfqq after splitting" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 1ba0403ac6447f2d63914fb760c44a3b19c44eaf # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100222-aliens-ergonomic-4ce2@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: 1ba0403ac644 ("block, bfq: fix uaf for accessing waker_bfqq after splitting") fd571df0ac5b ("block, bfq: turn bfqq_data into an array in bfq_io_cq") a61230470c8c ("block, bfq: move io_cq-persistent bfqq data into a dedicated struct") 9778369a2d6c ("block, bfq: split sync bfq_queues on a per-actuator basis") 246cf66e300b ("block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq") 337366e02b37 ("block, bfq: replace 0/1 with false/true in bic apis") 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'") a1795c2ccb1e ("bfq: fix waker_bfqq inconsistency crash") dc469ba2e790 ("block/bfq: Use the new blk_opf_t type") f950667356ce ("bfq: Relax waker detection for shared queues") 4e54a2493e58 ("bfq: Get rid of __bio_blkcg() usage") 09f871868080 ("bfq: Track whether bfq_group is still online") ea591cd4eb27 ("bfq: Update cgroup information before merging bio") 3bc5e683c67d ("bfq: Split shared queues on move between cgroups") 70456e5210f4 ("bfq: Avoid false marking of bic as stably merged") f6bad159f5d5 ("block/bfq-iosched.c: use "false" rather than "BLK_RW_ASYNC"") a0725c22cd84 ("bfq: use bfq_bic_lookup in bfq_limit_depth") 1f18b7005b49 ("bfq: Limit waker detection in time") 76f1df88bbc2 ("bfq: Limit number of requests consumed by each cgroup") 44dfa279f117 ("bfq: Store full bitmap depth in bfq_data") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 1ba0403ac6447f2d63914fb760c44a3b19c44eaf Mon Sep 17 00:00:00 2001 From: Yu Kuai <yukuai3(a)huawei.com> Date: Mon, 9 Sep 2024 21:41:48 +0800 Subject: [PATCH] block, bfq: fix uaf for accessing waker_bfqq after splitting After commit 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()"), if the current procress is the last holder of bfqq, the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq may in the merge chain of bfqq, hence just recored waker_bfqq is still not safe. Fix the problem by adding a helper bfq_waker_bfqq() to check if bfqq->waker_bfqq is in the merge chain, and current procress is the only holder. Fixes: 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()") Signed-off-by: Yu Kuai <yukuai3(a)huawei.com> Link: https://lore.kernel.org/r/20240909134154.954924-2-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index d1bf2b8a3576..d5d39974c674 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -6825,6 +6825,31 @@ static void bfq_prepare_request(struct request *rq) rq->elv.priv[0] = rq->elv.priv[1] = NULL; } +static struct bfq_queue *bfq_waker_bfqq(struct bfq_queue *bfqq) +{ + struct bfq_queue *new_bfqq = bfqq->new_bfqq; + struct bfq_queue *waker_bfqq = bfqq->waker_bfqq; + + if (!waker_bfqq) + return NULL; + + while (new_bfqq) { + if (new_bfqq == waker_bfqq) { + /* + * If waker_bfqq is in the merge chain, and current + * is the only procress. + */ + if (bfqq_process_refs(waker_bfqq) == 1) + return NULL; + break; + } + + new_bfqq = new_bfqq->new_bfqq; + } + + return waker_bfqq; +} + /* * If needed, init rq, allocate bfq data structures associated with * rq, and increment reference counters in the destination bfq_queue @@ -6886,7 +6911,7 @@ static struct bfq_queue *bfq_init_rq(struct request *rq) /* If the queue was seeky for too long, break it apart. */ if (bfq_bfqq_coop(bfqq) && bfq_bfqq_split_coop(bfqq) && !bic->bfqq_data[a_idx].stably_merged) { - struct bfq_queue *old_bfqq = bfqq; + struct bfq_queue *waker_bfqq = bfq_waker_bfqq(bfqq); /* Update bic before losing reference to bfqq */ if (bfq_bfqq_in_large_burst(bfqq)) @@ -6906,7 +6931,7 @@ static struct bfq_queue *bfq_init_rq(struct request *rq) bfqq_already_existing = true; if (!bfqq_already_existing) { - bfqq->waker_bfqq = old_bfqq->waker_bfqq; + bfqq->waker_bfqq = waker_bfqq; bfqq->tentative_waker_bfqq = NULL; /* @@ -6916,7 +6941,7 @@ static struct bfq_queue *bfq_init_rq(struct request *rq) * woken_list of the waker. See * bfq_check_waker for details. */ - if (bfqq->waker_bfqq) + if (waker_bfqq) hlist_add_head(&bfqq->woken_list_node, &bfqq->waker_bfqq->woken_list); }

9 months

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FAILED: patch "[PATCH] block, bfq: fix uaf for accessing waker_bfqq after splitting" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 1ba0403ac6447f2d63914fb760c44a3b19c44eaf # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100221-radar-unethical-0eaa@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: 1ba0403ac644 ("block, bfq: fix uaf for accessing waker_bfqq after splitting") fd571df0ac5b ("block, bfq: turn bfqq_data into an array in bfq_io_cq") a61230470c8c ("block, bfq: move io_cq-persistent bfqq data into a dedicated struct") 9778369a2d6c ("block, bfq: split sync bfq_queues on a per-actuator basis") 246cf66e300b ("block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq") 337366e02b37 ("block, bfq: replace 0/1 with false/true in bic apis") 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'") a1795c2ccb1e ("bfq: fix waker_bfqq inconsistency crash") dc469ba2e790 ("block/bfq: Use the new blk_opf_t type") f950667356ce ("bfq: Relax waker detection for shared queues") 4e54a2493e58 ("bfq: Get rid of __bio_blkcg() usage") 09f871868080 ("bfq: Track whether bfq_group is still online") ea591cd4eb27 ("bfq: Update cgroup information before merging bio") 3bc5e683c67d ("bfq: Split shared queues on move between cgroups") 70456e5210f4 ("bfq: Avoid false marking of bic as stably merged") f6bad159f5d5 ("block/bfq-iosched.c: use "false" rather than "BLK_RW_ASYNC"") a0725c22cd84 ("bfq: use bfq_bic_lookup in bfq_limit_depth") 1f18b7005b49 ("bfq: Limit waker detection in time") 76f1df88bbc2 ("bfq: Limit number of requests consumed by each cgroup") 44dfa279f117 ("bfq: Store full bitmap depth in bfq_data") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 1ba0403ac6447f2d63914fb760c44a3b19c44eaf Mon Sep 17 00:00:00 2001 From: Yu Kuai <yukuai3(a)huawei.com> Date: Mon, 9 Sep 2024 21:41:48 +0800 Subject: [PATCH] block, bfq: fix uaf for accessing waker_bfqq after splitting After commit 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()"), if the current procress is the last holder of bfqq, the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq may in the merge chain of bfqq, hence just recored waker_bfqq is still not safe. Fix the problem by adding a helper bfq_waker_bfqq() to check if bfqq->waker_bfqq is in the merge chain, and current procress is the only holder. Fixes: 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()") Signed-off-by: Yu Kuai <yukuai3(a)huawei.com> Link: https://lore.kernel.org/r/20240909134154.954924-2-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index d1bf2b8a3576..d5d39974c674 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -6825,6 +6825,31 @@ static void bfq_prepare_request(struct request *rq) rq->elv.priv[0] = rq->elv.priv[1] = NULL; } +static struct bfq_queue *bfq_waker_bfqq(struct bfq_queue *bfqq) +{ + struct bfq_queue *new_bfqq = bfqq->new_bfqq; + struct bfq_queue *waker_bfqq = bfqq->waker_bfqq; + + if (!waker_bfqq) + return NULL; + + while (new_bfqq) { + if (new_bfqq == waker_bfqq) { + /* + * If waker_bfqq is in the merge chain, and current + * is the only procress. + */ + if (bfqq_process_refs(waker_bfqq) == 1) + return NULL; + break; + } + + new_bfqq = new_bfqq->new_bfqq; + } + + return waker_bfqq; +} + /* * If needed, init rq, allocate bfq data structures associated with * rq, and increment reference counters in the destination bfq_queue @@ -6886,7 +6911,7 @@ static struct bfq_queue *bfq_init_rq(struct request *rq) /* If the queue was seeky for too long, break it apart. */ if (bfq_bfqq_coop(bfqq) && bfq_bfqq_split_coop(bfqq) && !bic->bfqq_data[a_idx].stably_merged) { - struct bfq_queue *old_bfqq = bfqq; + struct bfq_queue *waker_bfqq = bfq_waker_bfqq(bfqq); /* Update bic before losing reference to bfqq */ if (bfq_bfqq_in_large_burst(bfqq)) @@ -6906,7 +6931,7 @@ static struct bfq_queue *bfq_init_rq(struct request *rq) bfqq_already_existing = true; if (!bfqq_already_existing) { - bfqq->waker_bfqq = old_bfqq->waker_bfqq; + bfqq->waker_bfqq = waker_bfqq; bfqq->tentative_waker_bfqq = NULL; /* @@ -6916,7 +6941,7 @@ static struct bfq_queue *bfq_init_rq(struct request *rq) * woken_list of the waker. See * bfq_check_waker for details. */ - if (bfqq->waker_bfqq) + if (waker_bfqq) hlist_add_head(&bfqq->woken_list_node, &bfqq->waker_bfqq->woken_list); }

9 months

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FAILED: patch "[PATCH] block, bfq: fix uaf for accessing waker_bfqq after splitting" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 1ba0403ac6447f2d63914fb760c44a3b19c44eaf # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100221-pang-residue-68ad@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: 1ba0403ac644 ("block, bfq: fix uaf for accessing waker_bfqq after splitting") fd571df0ac5b ("block, bfq: turn bfqq_data into an array in bfq_io_cq") a61230470c8c ("block, bfq: move io_cq-persistent bfqq data into a dedicated struct") 9778369a2d6c ("block, bfq: split sync bfq_queues on a per-actuator basis") 246cf66e300b ("block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq") 337366e02b37 ("block, bfq: replace 0/1 with false/true in bic apis") 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'") a1795c2ccb1e ("bfq: fix waker_bfqq inconsistency crash") dc469ba2e790 ("block/bfq: Use the new blk_opf_t type") f950667356ce ("bfq: Relax waker detection for shared queues") 4e54a2493e58 ("bfq: Get rid of __bio_blkcg() usage") 09f871868080 ("bfq: Track whether bfq_group is still online") ea591cd4eb27 ("bfq: Update cgroup information before merging bio") 3bc5e683c67d ("bfq: Split shared queues on move between cgroups") 70456e5210f4 ("bfq: Avoid false marking of bic as stably merged") f6bad159f5d5 ("block/bfq-iosched.c: use "false" rather than "BLK_RW_ASYNC"") a0725c22cd84 ("bfq: use bfq_bic_lookup in bfq_limit_depth") 1f18b7005b49 ("bfq: Limit waker detection in time") 76f1df88bbc2 ("bfq: Limit number of requests consumed by each cgroup") 44dfa279f117 ("bfq: Store full bitmap depth in bfq_data") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 1ba0403ac6447f2d63914fb760c44a3b19c44eaf Mon Sep 17 00:00:00 2001 From: Yu Kuai <yukuai3(a)huawei.com> Date: Mon, 9 Sep 2024 21:41:48 +0800 Subject: [PATCH] block, bfq: fix uaf for accessing waker_bfqq after splitting After commit 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()"), if the current procress is the last holder of bfqq, the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq may in the merge chain of bfqq, hence just recored waker_bfqq is still not safe. Fix the problem by adding a helper bfq_waker_bfqq() to check if bfqq->waker_bfqq is in the merge chain, and current procress is the only holder. Fixes: 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()") Signed-off-by: Yu Kuai <yukuai3(a)huawei.com> Link: https://lore.kernel.org/r/20240909134154.954924-2-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index d1bf2b8a3576..d5d39974c674 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -6825,6 +6825,31 @@ static void bfq_prepare_request(struct request *rq) rq->elv.priv[0] = rq->elv.priv[1] = NULL; } +static struct bfq_queue *bfq_waker_bfqq(struct bfq_queue *bfqq) +{ + struct bfq_queue *new_bfqq = bfqq->new_bfqq; + struct bfq_queue *waker_bfqq = bfqq->waker_bfqq; + + if (!waker_bfqq) + return NULL; + + while (new_bfqq) { + if (new_bfqq == waker_bfqq) { + /* + * If waker_bfqq is in the merge chain, and current + * is the only procress. + */ + if (bfqq_process_refs(waker_bfqq) == 1) + return NULL; + break; + } + + new_bfqq = new_bfqq->new_bfqq; + } + + return waker_bfqq; +} + /* * If needed, init rq, allocate bfq data structures associated with * rq, and increment reference counters in the destination bfq_queue @@ -6886,7 +6911,7 @@ static struct bfq_queue *bfq_init_rq(struct request *rq) /* If the queue was seeky for too long, break it apart. */ if (bfq_bfqq_coop(bfqq) && bfq_bfqq_split_coop(bfqq) && !bic->bfqq_data[a_idx].stably_merged) { - struct bfq_queue *old_bfqq = bfqq; + struct bfq_queue *waker_bfqq = bfq_waker_bfqq(bfqq); /* Update bic before losing reference to bfqq */ if (bfq_bfqq_in_large_burst(bfqq)) @@ -6906,7 +6931,7 @@ static struct bfq_queue *bfq_init_rq(struct request *rq) bfqq_already_existing = true; if (!bfqq_already_existing) { - bfqq->waker_bfqq = old_bfqq->waker_bfqq; + bfqq->waker_bfqq = waker_bfqq; bfqq->tentative_waker_bfqq = NULL; /* @@ -6916,7 +6941,7 @@ static struct bfq_queue *bfq_init_rq(struct request *rq) * woken_list of the waker. See * bfq_check_waker for details. */ - if (bfqq->waker_bfqq) + if (waker_bfqq) hlist_add_head(&bfqq->woken_list_node, &bfqq->waker_bfqq->woken_list); }

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