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

+ mm-damon-sysfs-fix-use-after-free-in-state_show.patch added to mm-hotfixes-unstable branch

by Andrew Morton

The patch titled Subject: mm/damon/sysfs: fix use-after-free in state_show() has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-damon-sysfs-fix-use-after-free-in-state_show.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Stanislav Fort <stanislav.fort(a)aisle.com> Subject: mm/damon/sysfs: fix use-after-free in state_show() Date: Fri, 5 Sep 2025 13:10:46 +0300 state_show() reads kdamond->damon_ctx without holding damon_sysfs_lock. This allows a use-after-free race: CPU 0 CPU 1 ----- ----- state_show() damon_sysfs_turn_damon_on() ctx = kdamond->damon_ctx; mutex_lock(&damon_sysfs_lock); damon_destroy_ctx(kdamond->damon_ctx); kdamond->damon_ctx = NULL; mutex_unlock(&damon_sysfs_lock); damon_is_running(ctx); /* ctx is freed */ mutex_lock(&ctx->kdamond_lock); /* UAF */ (The race can also occur with damon_sysfs_kdamonds_rm_dirs() and damon_sysfs_kdamond_release(), which free or replace the context under damon_sysfs_lock.) Fix by taking damon_sysfs_lock before dereferencing the context, mirroring the locking used in pid_show(). The bug has existed since state_show() first accessed kdamond->damon_ctx. Link: https://lkml.kernel.org/r/20250905101046.2288-1-disclosure@aisle.com Fixes: a61ea561c871 ("mm/damon/sysfs: link DAMON for virtual address spaces monitoring") Signed-off-by: Stanislav Fort <disclosure(a)aisle.com> Reported-by: Stanislav Fort <disclosure(a)aisle.com> Reviewed-by: SeongJae Park <sj(a)kernel.org> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/damon/sysfs.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) --- a/mm/damon/sysfs.c~mm-damon-sysfs-fix-use-after-free-in-state_show +++ a/mm/damon/sysfs.c @@ -1260,14 +1260,18 @@ static ssize_t state_show(struct kobject { struct damon_sysfs_kdamond *kdamond = container_of(kobj, struct damon_sysfs_kdamond, kobj); - struct damon_ctx *ctx = kdamond->damon_ctx; - bool running; + struct damon_ctx *ctx; + bool running = false; - if (!ctx) - running = false; - else + if (!mutex_trylock(&damon_sysfs_lock)) + return -EBUSY; + + ctx = kdamond->damon_ctx; + if (ctx) running = damon_is_running(ctx); + mutex_unlock(&damon_sysfs_lock); + return sysfs_emit(buf, "%s\n", running ? damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_ON] : damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_OFF]); _ Patches currently in -mm which might be from stanislav.fort(a)aisle.com are mm-damon-sysfs-fix-use-after-free-in-state_show.patch

1 week, 2 days

1
0
0 0

FAILED: patch "[PATCH] ALSA: hda/realtek - Add new HP ZBook laptop with micmute led" 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 f709b78aecab519dbcefa9a6603b94ad18c553e3 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025052421-diffusion-untimely-a099@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f709b78aecab519dbcefa9a6603b94ad18c553e3 Mon Sep 17 00:00:00 2001 From: Chris Chiu <chris.chiu(a)canonical.com> Date: Tue, 20 May 2025 21:21:01 +0800 Subject: [PATCH] ALSA: hda/realtek - Add new HP ZBook laptop with micmute led fixup New HP ZBook with Realtek HDA codec ALC3247 needs the quirk ALC236_FIXUP_HP_GPIO_LED to fix the micmute LED. Signed-off-by: Chris Chiu <chris.chiu(a)canonical.com> Cc: <stable(a)vger.kernel.org> Link: https://patch.msgid.link/20250520132101.120685-1-chris.chiu@canonical.com Signed-off-by: Takashi Iwai <tiwai(a)suse.de> diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c index 69788dd9a1ec..20ab1fb2195f 100644 --- a/sound/pci/hda/patch_realtek.c +++ b/sound/pci/hda/patch_realtek.c @@ -10885,6 +10885,7 @@ static const struct hda_quirk alc269_fixup_tbl[] = { SND_PCI_QUIRK(0x103c, 0x8e1a, "HP ZBook Firefly 14 G12A", ALC245_FIXUP_HP_ZBOOK_FIREFLY_G12A), SND_PCI_QUIRK(0x103c, 0x8e1b, "HP EliteBook G12", ALC245_FIXUP_HP_ZBOOK_FIREFLY_G12A), SND_PCI_QUIRK(0x103c, 0x8e1c, "HP EliteBook G12", ALC245_FIXUP_HP_ZBOOK_FIREFLY_G12A), + SND_PCI_QUIRK(0x103c, 0x8e1d, "HP ZBook X Gli 16 G12", ALC236_FIXUP_HP_GPIO_LED), SND_PCI_QUIRK(0x103c, 0x8e2c, "HP EliteBook 16 G12", ALC285_FIXUP_HP_GPIO_LED), SND_PCI_QUIRK(0x103c, 0x8e36, "HP 14 Enstrom OmniBook X", ALC287_FIXUP_CS35L41_I2C_2), SND_PCI_QUIRK(0x103c, 0x8e37, "HP 16 Piston OmniBook X", ALC287_FIXUP_CS35L41_I2C_2),

1 week, 2 days

2
1
0 0

FAILED: patch "[PATCH] ALSA: hda/realtek - Add new HP ZBook laptop with micmute led" 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 f709b78aecab519dbcefa9a6603b94ad18c553e3 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025052421-document-satirical-8e58@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f709b78aecab519dbcefa9a6603b94ad18c553e3 Mon Sep 17 00:00:00 2001 From: Chris Chiu <chris.chiu(a)canonical.com> Date: Tue, 20 May 2025 21:21:01 +0800 Subject: [PATCH] ALSA: hda/realtek - Add new HP ZBook laptop with micmute led fixup New HP ZBook with Realtek HDA codec ALC3247 needs the quirk ALC236_FIXUP_HP_GPIO_LED to fix the micmute LED. Signed-off-by: Chris Chiu <chris.chiu(a)canonical.com> Cc: <stable(a)vger.kernel.org> Link: https://patch.msgid.link/20250520132101.120685-1-chris.chiu@canonical.com Signed-off-by: Takashi Iwai <tiwai(a)suse.de> diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c index 69788dd9a1ec..20ab1fb2195f 100644 --- a/sound/pci/hda/patch_realtek.c +++ b/sound/pci/hda/patch_realtek.c @@ -10885,6 +10885,7 @@ static const struct hda_quirk alc269_fixup_tbl[] = { SND_PCI_QUIRK(0x103c, 0x8e1a, "HP ZBook Firefly 14 G12A", ALC245_FIXUP_HP_ZBOOK_FIREFLY_G12A), SND_PCI_QUIRK(0x103c, 0x8e1b, "HP EliteBook G12", ALC245_FIXUP_HP_ZBOOK_FIREFLY_G12A), SND_PCI_QUIRK(0x103c, 0x8e1c, "HP EliteBook G12", ALC245_FIXUP_HP_ZBOOK_FIREFLY_G12A), + SND_PCI_QUIRK(0x103c, 0x8e1d, "HP ZBook X Gli 16 G12", ALC236_FIXUP_HP_GPIO_LED), SND_PCI_QUIRK(0x103c, 0x8e2c, "HP EliteBook 16 G12", ALC285_FIXUP_HP_GPIO_LED), SND_PCI_QUIRK(0x103c, 0x8e36, "HP 14 Enstrom OmniBook X", ALC287_FIXUP_CS35L41_I2C_2), SND_PCI_QUIRK(0x103c, 0x8e37, "HP 16 Piston OmniBook X", ALC287_FIXUP_CS35L41_I2C_2),

1 week, 2 days

2
1
0 0

[PATCH] ARM: OMAP2+: pm33xx-core: ix device node reference leaks in amx3_idle_init

by Miaoqian Lin

Add missing of_node_put() calls to release device node references obtained via of_parse_phandle(). Fixes: 06ee7a950b6a ("ARM: OMAP2+: pm33xx-core: Add cpuidle_ops for am335x/am437x") Cc: stable(a)vger.kernel.org Signed-off-by: Miaoqian Lin <linmq006(a)gmail.com> --- arch/arm/mach-omap2/pm33xx-core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-omap2/pm33xx-core.c b/arch/arm/mach-omap2/pm33xx-core.c index c907478be196..4abb86dc98fd 100644 --- a/arch/arm/mach-omap2/pm33xx-core.c +++ b/arch/arm/mach-omap2/pm33xx-core.c @@ -388,12 +388,15 @@ static int __init amx3_idle_init(struct device_node *cpu_node, int cpu) if (!state_node) break; - if (!of_device_is_available(state_node)) + if (!of_device_is_available(state_node)) { + of_node_put(state_node); continue; + } if (i == CPUIDLE_STATE_MAX) { pr_warn("%s: cpuidle states reached max possible\n", __func__); + of_node_put(state_node); break; } @@ -403,6 +406,7 @@ static int __init amx3_idle_init(struct device_node *cpu_node, int cpu) states[state_count].wfi_flags |= WFI_FLAG_WAKE_M3 | WFI_FLAG_FLUSH_CACHE; + of_node_put(state_node); state_count++; } -- 2.35.1

1 week, 2 days

3
2
0 0

[PATCH] ARM: AM33xx: Implement TI advisory 1.0.36 (EMU0/EMU1 pins state on reset)

by A. Sverdlin

From: Alexander Sverdlin <alexander.sverdlin(a)siemens.com> There is an issue possible where TI AM33xx SoCs do not boot properly after a reset if EMU0/EMU1 pins were used as GPIO and have been driving low level actively prior to reset [1]. "Advisory 1.0.36 EMU0 and EMU1: Terminals Must be Pulled High Before ICEPick Samples The state of the EMU[1:0] terminals are latched during reset to determine ICEPick boot mode. For normal device operation, these terminals must be pulled up to a valid high logic level ( > VIH min) before ICEPick samples the state of these terminals, which occurs [five CLK_M_OSC clock cycles - 10 ns] after the falling edge of WARMRSTn. Many applications may not require the secondary GPIO function of the EMU[1:0] terminals. In this case, they would only be connected to pull-up resistors, which ensures they are always high when ICEPick samples. However, some applications may need to use these terminals as GPIO where they could be driven low before reset is asserted. This usage of the EMU[1:0] terminals may require special attention to ensure the terminals are allowed to return to a valid high-logic level before ICEPick samples the state of these terminals. When any device reset is asserted, the pin mux mode of EMU[1:0] terminals configured to operate as GPIO (mode 7) will change back to EMU input (mode 0) on the falling edge of WARMRSTn. This only provides a short period of time for the terminals to return high if driven low before reset is asserted... If the EMU[1:0] terminals are configured to operate as GPIO, the product should be designed such these terminals can be pulled to a valid high-logic level within 190 ns after the falling edge of WARMRSTn." We've noticed this problem with custom am335x hardware in combination with recently implemented cold reset method (commit 6521f6a195c70 ("ARM: AM33xx: PRM: Implement REBOOT_COLD")). It looks like the problem can affect other HW, for instance AM335x Chiliboard, because the latter has LEDs on GPIO3_7/GPIO3_8 as well. One option would be to check if the pins are in GPIO mode and either switch to output active high, or switch to input and poll until the external pull-ups have brought the pins to the desired high state. But fighting with GPIO driver for these pins is probably not the most straight forward approch in a reboot handler. Fortunately we can easily control pinmuxing here and rely on the external pull-ups. TI recommends 4k7 external pull up resistors [2] and even with quite conservative estimation for pin capacity (1 uF should never happen) the required delay shall not exceed 5ms. [1] Link: https://www.ti.com/lit/pdf/sprz360 [2] Link: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/8… Cc: stable(a)vger.kernel.org Signed-off-by: Alexander Sverdlin <alexander.sverdlin(a)siemens.com> --- arch/arm/mach-omap2/am33xx-restart.c | 36 ++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/arch/arm/mach-omap2/am33xx-restart.c b/arch/arm/mach-omap2/am33xx-restart.c index fcf3d557aa786..3cdf223addcc2 100644 --- a/arch/arm/mach-omap2/am33xx-restart.c +++ b/arch/arm/mach-omap2/am33xx-restart.c @@ -2,12 +2,46 @@ /* * am33xx-restart.c - Code common to all AM33xx machines. */ +#include <dt-bindings/pinctrl/am33xx.h> +#include <linux/delay.h> #include <linux/kernel.h> #include <linux/reboot.h> #include "common.h" +#include "control.h" #include "prm.h" +/* + * Advisory 1.0.36 EMU0 and EMU1: Terminals Must be Pulled High Before + * ICEPick Samples + * + * If EMU0/EMU1 pins have been used as GPIO outputs and actively driving low + * level, the device might not reboot in normal mode. We are in a bad position + * to override GPIO state here, so just switch the pins into EMU input mode + * (that's what reset will do anyway) and wait a bit, because the state will be + * latched 190 ns after reset. + */ +static void am33xx_advisory_1_0_36(void) +{ + u32 emu0 = omap_ctrl_readl(AM335X_PIN_EMU0); + u32 emu1 = omap_ctrl_readl(AM335X_PIN_EMU1); + + /* If both pins are in EMU mode, nothing to do */ + if (!(emu0 & 7) && !(emu1 & 7)) + return; + + /* Switch GPIO3_7/GPIO3_8 into EMU0/EMU1 modes respectively */ + omap_ctrl_writel(emu0 & ~7, AM335X_PIN_EMU0); + omap_ctrl_writel(emu1 & ~7, AM335X_PIN_EMU1); + + /* + * Give pull-ups time to load the pin/PCB trace capacity. + * 5 ms shall be enough to load 1 uF (would be huge capacity for these + * pins) with TI-recommended 4k7 external pull-ups. + */ + mdelay(5); +} + /** * am33xx_restart - trigger a software restart of the SoC * @mode: the "reboot mode", see arch/arm/kernel/{setup,process}.c @@ -18,6 +52,8 @@ */ void am33xx_restart(enum reboot_mode mode, const char *cmd) { + am33xx_advisory_1_0_36(); + /* TODO: Handle cmd if necessary */ prm_reboot_mode = mode; -- 2.50.1

1 week, 2 days

2
1
0 0

[PATCH 0/2] Fix riscv sparse warnings

by Alexandre Ghiti

This series simply fixes 2 recently introduced sparse warnings. Signed-off-by: Alexandre Ghiti <alexghiti(a)rivosinc.com> --- Alexandre Ghiti (2): riscv: Fix sparse warning in __get_user_error() riscv: Fix sparse warning about different address spaces arch/riscv/include/asm/uaccess.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- base-commit: ae9a687664d965b13eeab276111b2f97dd02e090 change-id: 20250903-dev-alex-sparse_warnings_v1-ecb4a333afdd Best regards, -- Alexandre Ghiti <alexghiti(a)rivosinc.com>

1 week, 2 days

4
8
0 0

FAILED: patch "[PATCH] dmaengine: mediatek: Fix a possible deadlock error in" 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 157ae5ffd76a2857ccb4b7ce40bc5a344ca00395 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051913-detached-security-c641@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 157ae5ffd76a2857ccb4b7ce40bc5a344ca00395 Mon Sep 17 00:00:00 2001 From: Qiu-ji Chen <chenqiuji666(a)gmail.com> Date: Thu, 8 May 2025 15:36:33 +0800 Subject: [PATCH] dmaengine: mediatek: Fix a possible deadlock error in mtk_cqdma_tx_status() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fix a potential deadlock bug. Observe that in the mtk-cqdma.c file, functions like mtk_cqdma_issue_pending() and mtk_cqdma_free_active_desc() properly acquire the pc lock before the vc lock when handling pc and vc fields. However, mtk_cqdma_tx_status() violates this order by first acquiring the vc lock before invoking mtk_cqdma_find_active_desc(), which subsequently takes the pc lock. This reversed locking sequence (vc → pc) contradicts the established pc → vc order and creates deadlock risks. Fix the issue by moving the vc lock acquisition code from mtk_cqdma_find_active_desc() to mtk_cqdma_tx_status(). Ensure the pc lock is acquired before the vc lock in the calling function to maintain correct locking hierarchy. Note that since mtk_cqdma_find_active_desc() is a static function with only one caller (mtk_cqdma_tx_status()), this modification safely eliminates the deadlock possibility without affecting other components. This possible bug is found by an experimental static analysis tool developed by our team. This tool analyzes the locking APIs to extract function pairs that can be concurrently executed, and then analyzes the instructions in the paired functions to identify possible concurrency bugs including deadlocks, data races and atomicity violations. Fixes: b1f01e48df5a ("dmaengine: mediatek: Add MediaTek Command-Queue DMA controller for MT6765 SoC") Cc: stable(a)vger.kernel.org Signed-off-by: Qiu-ji Chen <chenqiuji666(a)gmail.com> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno(a)collabora.com> Link: https://lore.kernel.org/r/20250508073634.3719-1-chenqiuji666@gmail.com Signed-off-by: Vinod Koul <vkoul(a)kernel.org> diff --git a/drivers/dma/mediatek/mtk-cqdma.c b/drivers/dma/mediatek/mtk-cqdma.c index d5ddb4e30e71..e35271ac1eed 100644 --- a/drivers/dma/mediatek/mtk-cqdma.c +++ b/drivers/dma/mediatek/mtk-cqdma.c @@ -422,13 +422,10 @@ static struct virt_dma_desc *mtk_cqdma_find_active_desc(struct dma_chan *c, struct virt_dma_desc *vd; unsigned long flags; - spin_lock_irqsave(&cvc->pc->lock, flags); list_for_each_entry(vd, &cvc->pc->queue, node) if (vd->tx.cookie == cookie) { - spin_unlock_irqrestore(&cvc->pc->lock, flags); return vd; } - spin_unlock_irqrestore(&cvc->pc->lock, flags); list_for_each_entry(vd, &cvc->vc.desc_issued, node) if (vd->tx.cookie == cookie) @@ -452,9 +449,11 @@ static enum dma_status mtk_cqdma_tx_status(struct dma_chan *c, if (ret == DMA_COMPLETE || !txstate) return ret; + spin_lock_irqsave(&cvc->pc->lock, flags); spin_lock_irqsave(&cvc->vc.lock, flags); vd = mtk_cqdma_find_active_desc(c, cookie); spin_unlock_irqrestore(&cvc->vc.lock, flags); + spin_unlock_irqrestore(&cvc->pc->lock, flags); if (vd) { cvd = to_cqdma_vdesc(vd);

1 week, 2 days

2
1
0 0

FAILED: patch "[PATCH] dmaengine: mediatek: Fix a possible deadlock error in" 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 157ae5ffd76a2857ccb4b7ce40bc5a344ca00395 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051909-laziness-boss-78ae@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 157ae5ffd76a2857ccb4b7ce40bc5a344ca00395 Mon Sep 17 00:00:00 2001 From: Qiu-ji Chen <chenqiuji666(a)gmail.com> Date: Thu, 8 May 2025 15:36:33 +0800 Subject: [PATCH] dmaengine: mediatek: Fix a possible deadlock error in mtk_cqdma_tx_status() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fix a potential deadlock bug. Observe that in the mtk-cqdma.c file, functions like mtk_cqdma_issue_pending() and mtk_cqdma_free_active_desc() properly acquire the pc lock before the vc lock when handling pc and vc fields. However, mtk_cqdma_tx_status() violates this order by first acquiring the vc lock before invoking mtk_cqdma_find_active_desc(), which subsequently takes the pc lock. This reversed locking sequence (vc → pc) contradicts the established pc → vc order and creates deadlock risks. Fix the issue by moving the vc lock acquisition code from mtk_cqdma_find_active_desc() to mtk_cqdma_tx_status(). Ensure the pc lock is acquired before the vc lock in the calling function to maintain correct locking hierarchy. Note that since mtk_cqdma_find_active_desc() is a static function with only one caller (mtk_cqdma_tx_status()), this modification safely eliminates the deadlock possibility without affecting other components. This possible bug is found by an experimental static analysis tool developed by our team. This tool analyzes the locking APIs to extract function pairs that can be concurrently executed, and then analyzes the instructions in the paired functions to identify possible concurrency bugs including deadlocks, data races and atomicity violations. Fixes: b1f01e48df5a ("dmaengine: mediatek: Add MediaTek Command-Queue DMA controller for MT6765 SoC") Cc: stable(a)vger.kernel.org Signed-off-by: Qiu-ji Chen <chenqiuji666(a)gmail.com> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno(a)collabora.com> Link: https://lore.kernel.org/r/20250508073634.3719-1-chenqiuji666@gmail.com Signed-off-by: Vinod Koul <vkoul(a)kernel.org> diff --git a/drivers/dma/mediatek/mtk-cqdma.c b/drivers/dma/mediatek/mtk-cqdma.c index d5ddb4e30e71..e35271ac1eed 100644 --- a/drivers/dma/mediatek/mtk-cqdma.c +++ b/drivers/dma/mediatek/mtk-cqdma.c @@ -422,13 +422,10 @@ static struct virt_dma_desc *mtk_cqdma_find_active_desc(struct dma_chan *c, struct virt_dma_desc *vd; unsigned long flags; - spin_lock_irqsave(&cvc->pc->lock, flags); list_for_each_entry(vd, &cvc->pc->queue, node) if (vd->tx.cookie == cookie) { - spin_unlock_irqrestore(&cvc->pc->lock, flags); return vd; } - spin_unlock_irqrestore(&cvc->pc->lock, flags); list_for_each_entry(vd, &cvc->vc.desc_issued, node) if (vd->tx.cookie == cookie) @@ -452,9 +449,11 @@ static enum dma_status mtk_cqdma_tx_status(struct dma_chan *c, if (ret == DMA_COMPLETE || !txstate) return ret; + spin_lock_irqsave(&cvc->pc->lock, flags); spin_lock_irqsave(&cvc->vc.lock, flags); vd = mtk_cqdma_find_active_desc(c, cookie); spin_unlock_irqrestore(&cvc->vc.lock, flags); + spin_unlock_irqrestore(&cvc->pc->lock, flags); if (vd) { cvd = to_cqdma_vdesc(vd);

1 week, 2 days

2
1
0 0

[PATCH] fs/ceph/dir: fix `i_nlink` underrun during async unlink

by Max Kellermann

During async unlink, we drop the `i_nlink` counter before we receive the completion (that will eventually update the `i_nlink`) because "we assume that the unlink will succeed". That is not a bad idea, but it races against deletions by other clients (or against the completion of our own unlink) and can lead to an underrun which emits a WARNING like this one: WARNING: CPU: 85 PID: 25093 at fs/inode.c:407 drop_nlink+0x50/0x68 Modules linked in: CPU: 85 UID: 3221252029 PID: 25093 Comm: php-cgi8.1 Not tainted 6.14.11-cm4all1-ampere #655 Hardware name: Supermicro ARS-110M-NR/R12SPD-A, BIOS 1.1b 10/17/2023 pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : drop_nlink+0x50/0x68 lr : ceph_unlink+0x6c4/0x720 sp : ffff80012173bc90 x29: ffff80012173bc90 x28: ffff086d0a45aaf8 x27: ffff0871d0eb5680 x26: ffff087f2a64a718 x25: 0000020000000180 x24: 0000000061c88647 x23: 0000000000000002 x22: ffff07ff9236d800 x21: 0000000000001203 x20: ffff07ff9237b000 x19: ffff088b8296afc0 x18: 00000000f3c93365 x17: 0000000000070000 x16: ffff08faffcbdfe8 x15: ffff08faffcbdfec x14: 0000000000000000 x13: 45445f65645f3037 x12: 34385f6369706f74 x11: 0000a2653104bb20 x10: ffffd85f26d73290 x9 : ffffd85f25664f94 x8 : 00000000000000c0 x7 : 0000000000000000 x6 : 0000000000000002 x5 : 0000000000000081 x4 : 0000000000000481 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff08727d3f91e8 Call trace: drop_nlink+0x50/0x68 (P) vfs_unlink+0xb0/0x2e8 do_unlinkat+0x204/0x288 __arm64_sys_unlinkat+0x3c/0x80 invoke_syscall.constprop.0+0x54/0xe8 do_el0_svc+0xa4/0xc8 el0_svc+0x18/0x58 el0t_64_sync_handler+0x104/0x130 el0t_64_sync+0x154/0x158 In ceph_unlink(), a call to ceph_mdsc_submit_request() submits the CEPH_MDS_OP_UNLINK to the MDS, but does not wait for completion. Meanwhile, between this call and the following drop_nlink() call, a worker thread may process a CEPH_CAP_OP_IMPORT, CEPH_CAP_OP_GRANT or just a CEPH_MSG_CLIENT_REPLY (the latter of which could be our own completion). These will lead to a set_nlink() call, updating the `i_nlink` counter to the value received from the MDS. If that new `i_nlink` value happens to be zero, it is illegal to decrement it further. But that is exactly what ceph_unlink() will do then. The WARNING can be reproduced this way: 1. Force async unlink; only the async code path is affected. Having no real clue about Ceph internals, I was unable to find out why the MDS wouldn't give me the "Fxr" capabilities, so I patched get_caps_for_async_unlink() to always succeed. (Note that the WARNING dump above was found on an unpatched kernel, without this kludge - this is not a theoretical bug.) 2. Add a sleep call after ceph_mdsc_submit_request() so the unlink completion gets handled by a worker thread before drop_nlink() is called. This guarantees that the `i_nlink` is already zero before drop_nlink() runs. The solution is to skip the counter decrement when it is already zero, but doing so without a lock is still racy (TOCTOU). Since ceph_fill_inode() and handle_cap_grant() both hold the `ceph_inode_info.i_ceph_lock` spinlock while set_nlink() runs, this seems like the proper lock to protect the `i_nlink` updates. I found prior art in NFS and SMB (using `inode.i_lock`) and AFS (using `afs_vnode.cb_lock`). All three have the zero check as well. Fixes: 2ccb45462aea ("ceph: perform asynchronous unlink if we have sufficient caps") Cc: stable(a)vger.kernel.org Signed-off-by: Max Kellermann <max.kellermann(a)ionos.com> --- fs/ceph/dir.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index 8478e7e75df6..67f04e23f78a 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -1341,6 +1341,7 @@ static int ceph_unlink(struct inode *dir, struct dentry *dentry) struct ceph_client *cl = fsc->client; struct ceph_mds_client *mdsc = fsc->mdsc; struct inode *inode = d_inode(dentry); + struct ceph_inode_info *ci = ceph_inode(inode); struct ceph_mds_request *req; bool try_async = ceph_test_mount_opt(fsc, ASYNC_DIROPS); struct dentry *dn; @@ -1427,7 +1428,19 @@ static int ceph_unlink(struct inode *dir, struct dentry *dentry) * We have enough caps, so we assume that the unlink * will succeed. Fix up the target inode and dcache. */ - drop_nlink(inode); + + /* + * Protect the i_nlink update with i_ceph_lock + * to precent racing against ceph_fill_inode() + * handling our completion on a worker thread + * and don't decrement if i_nlink has already + * been updated to zero by this completion. + */ + spin_lock(&ci->i_ceph_lock); + if (inode->i_nlink > 0) + drop_nlink(inode); + spin_unlock(&ci->i_ceph_lock); + d_delete(dentry); } else { spin_lock(&fsc->async_unlink_conflict_lock); -- 2.47.2

1 week, 2 days

1
0
0 0

FAILED: patch "[PATCH] dmaengine: mediatek: Fix a possible deadlock error in" 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 157ae5ffd76a2857ccb4b7ce40bc5a344ca00395 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051905-paced-scrounger-571a@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 157ae5ffd76a2857ccb4b7ce40bc5a344ca00395 Mon Sep 17 00:00:00 2001 From: Qiu-ji Chen <chenqiuji666(a)gmail.com> Date: Thu, 8 May 2025 15:36:33 +0800 Subject: [PATCH] dmaengine: mediatek: Fix a possible deadlock error in mtk_cqdma_tx_status() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fix a potential deadlock bug. Observe that in the mtk-cqdma.c file, functions like mtk_cqdma_issue_pending() and mtk_cqdma_free_active_desc() properly acquire the pc lock before the vc lock when handling pc and vc fields. However, mtk_cqdma_tx_status() violates this order by first acquiring the vc lock before invoking mtk_cqdma_find_active_desc(), which subsequently takes the pc lock. This reversed locking sequence (vc → pc) contradicts the established pc → vc order and creates deadlock risks. Fix the issue by moving the vc lock acquisition code from mtk_cqdma_find_active_desc() to mtk_cqdma_tx_status(). Ensure the pc lock is acquired before the vc lock in the calling function to maintain correct locking hierarchy. Note that since mtk_cqdma_find_active_desc() is a static function with only one caller (mtk_cqdma_tx_status()), this modification safely eliminates the deadlock possibility without affecting other components. This possible bug is found by an experimental static analysis tool developed by our team. This tool analyzes the locking APIs to extract function pairs that can be concurrently executed, and then analyzes the instructions in the paired functions to identify possible concurrency bugs including deadlocks, data races and atomicity violations. Fixes: b1f01e48df5a ("dmaengine: mediatek: Add MediaTek Command-Queue DMA controller for MT6765 SoC") Cc: stable(a)vger.kernel.org Signed-off-by: Qiu-ji Chen <chenqiuji666(a)gmail.com> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno(a)collabora.com> Link: https://lore.kernel.org/r/20250508073634.3719-1-chenqiuji666@gmail.com Signed-off-by: Vinod Koul <vkoul(a)kernel.org> diff --git a/drivers/dma/mediatek/mtk-cqdma.c b/drivers/dma/mediatek/mtk-cqdma.c index d5ddb4e30e71..e35271ac1eed 100644 --- a/drivers/dma/mediatek/mtk-cqdma.c +++ b/drivers/dma/mediatek/mtk-cqdma.c @@ -422,13 +422,10 @@ static struct virt_dma_desc *mtk_cqdma_find_active_desc(struct dma_chan *c, struct virt_dma_desc *vd; unsigned long flags; - spin_lock_irqsave(&cvc->pc->lock, flags); list_for_each_entry(vd, &cvc->pc->queue, node) if (vd->tx.cookie == cookie) { - spin_unlock_irqrestore(&cvc->pc->lock, flags); return vd; } - spin_unlock_irqrestore(&cvc->pc->lock, flags); list_for_each_entry(vd, &cvc->vc.desc_issued, node) if (vd->tx.cookie == cookie) @@ -452,9 +449,11 @@ static enum dma_status mtk_cqdma_tx_status(struct dma_chan *c, if (ret == DMA_COMPLETE || !txstate) return ret; + spin_lock_irqsave(&cvc->pc->lock, flags); spin_lock_irqsave(&cvc->vc.lock, flags); vd = mtk_cqdma_find_active_desc(c, cookie); spin_unlock_irqrestore(&cvc->vc.lock, flags); + spin_unlock_irqrestore(&cvc->pc->lock, flags); if (vd) { cvd = to_cqdma_vdesc(vd);

1 week, 2 days

2
1
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

Linux-stable-mirror