fix: Prevent segfault by correctly handling dbus restarts in mender-update and mender-auth by michalkopczan · Pull Request #1880 · mendersoftware/mender

michalkopczan · 2026-01-16T11:20:34Z

Ticket: MEN-9144
Changelog: Prevent segfault by correctly handling dbus restarts in mender-update and mender-auth. Previously when systemctl stop dbus.socket or systemctl stop dbus was called, it resulted in mender-update segfault.

No tests, as we would need to create a way to stop dbus, wait for correct time etc. IMO not worth it - too much effort for too little gain.

mender-test-bot · 2026-01-16T11:21:03Z

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michalkopczan · 2026-01-16T11:49:01Z

@mender-test-bot start client pipeline

mender-test-bot · 2026-01-16T11:49:22Z

Hello 😺 I created a pipeline for you here: Pipeline-2267035160

Build Configuration Matrix

Key	Value
BUILD_BEAGLEBONEBLACK	true
BUILD_CLIENT	true
BUILD_QEMUX86_64_BIOS_GRUB	true
BUILD_QEMUX86_64_BIOS_GRUB_GPT	true
BUILD_QEMUX86_64_UEFI_GRUB	true
BUILD_VEXPRESS_QEMU	true
BUILD_VEXPRESS_QEMU_FLASH	true
BUILD_VEXPRESS_QEMU_UBOOT_UEFI_GRUB	true
INTEGRATION_REV	master
MENDER_BINARY_DELTA_REV	master
MENDER_CLIENT_SUBCOMPONENTS_REV	main
MENDER_CONFIGURE_MODULE_REV	master
MENDER_CONNECT_REV	master
MENDER_CONTAINER_MODULES_REV	main
MENDER_FLASH_REV	master
MENDER_REV	pull/1880/head
MONITOR_CLIENT_REV	master
RUN_INTEGRATION_TESTS	true
TEST_QEMUX86_64_BIOS_GRUB	true
TEST_QEMUX86_64_BIOS_GRUB_GPT	true
TEST_QEMUX86_64_UEFI_GRUB	true
TEST_VEXPRESS_QEMU	true
TEST_VEXPRESS_QEMU_FLASH	true
TEST_VEXPRESS_QEMU_UBOOT_UEFI_GRUB	true

vpodzime

Looks good to me. Thanks for working on this tough code!

vpodzime

Just one last nitpick. Thanks!

vpodzime · 2026-01-21T15:22:36Z

 	if (err != error::NoError) {
 		log::Error("Error when trying to poll for deployment: " + err.String());
+		// If we're here, no handler will be called, so we need to manually schedule the next
+		// deployment poll


Thanks for adding this comment. However, could you please extend it a bit? It's hard to follow why/how doing poster.PostEvent(StateEvent::Failure); from PollForDeploymentState doesn't result in scheduling a next deployment poll. I can see it in the code, but it would be nice to save future me and others from (re-)doing that digging. 😅

Sure, makes sense! Added.

michalkopczan · 2026-01-22T10:17:39Z

@mender-test-bot start client pipeline

mender-test-bot · 2026-01-22T10:18:02Z

Hello 😺 I created a pipeline for you here: Pipeline-2278522358

Build Configuration Matrix

Key	Value
BUILD_BEAGLEBONEBLACK	true
BUILD_CLIENT	true
BUILD_QEMUX86_64_BIOS_GRUB	true
BUILD_QEMUX86_64_BIOS_GRUB_GPT	true
BUILD_QEMUX86_64_UEFI_GRUB	true
BUILD_VEXPRESS_QEMU	true
BUILD_VEXPRESS_QEMU_FLASH	true
BUILD_VEXPRESS_QEMU_UBOOT_UEFI_GRUB	true
INTEGRATION_REV	master
MENDER_BINARY_DELTA_REV	master
MENDER_CLIENT_SUBCOMPONENTS_REV	main
MENDER_CONFIGURE_MODULE_REV	master
MENDER_CONNECT_REV	master
MENDER_CONTAINER_MODULES_REV	main
MENDER_FLASH_REV	master
MENDER_REV	pull/1880/head
MONITOR_CLIENT_REV	master
RUN_INTEGRATION_TESTS	true
TEST_QEMUX86_64_BIOS_GRUB	true
TEST_QEMUX86_64_BIOS_GRUB_GPT	true
TEST_QEMUX86_64_UEFI_GRUB	true
TEST_VEXPRESS_QEMU	true
TEST_VEXPRESS_QEMU_FLASH	true
TEST_VEXPRESS_QEMU_UBOOT_UEFI_GRUB	true

…pdate and mender-auth Ticket: MEN-9144 Changelog: Prevent segfault by correctly handling dbus restarts in mender-update and mender-auth. Previously when systemctl stop dbus.socket or systemctl stop dbus was called, it resulted in mender-update segfault. Signed-off-by: Michal Kopczan <michal.kopczan@northern.tech>

…g no handler to be called Ticket: MEN-9144 Changelog: Fix a hang when polling for deployment failed early causing no handler of API response to be called. Added handler call for this case, causing the deployment polling to continue. Signed-off-by: Michal Kopczan <michal.kopczan@northern.tech>

mender-test-bot · 2026-01-23T11:00:54Z

Merging these commits will result in the following changelog entries:

Changelogs

mender (MEN-9144-mender-client-segfaults-upon-dbus-shutdown)

New changes in mender since master:

Bug Fixes

Fix a hang when polling for deployment failed early causing no handler of API response
to be called. Added handler call for this case, causing the deployment polling
to continue.
(MEN-9144)
Prevent segfault by correctly handling dbus restarts in mender-update and mender-auth.
Previously when systemctl stop dbus.socket or systemctl stop dbus was called, it resulted in mender-update segfault.
(MEN-9144)

michalkopczan · 2026-01-23T11:01:42Z

@mender-test-bot start client pipeline

mender-test-bot · 2026-01-23T11:02:08Z

Hello 😺 I created a pipeline for you here: Pipeline-2281567760

Build Configuration Matrix

Key	Value
BUILD_BEAGLEBONEBLACK	true
BUILD_CLIENT	true
BUILD_QEMUX86_64_BIOS_GRUB	true
BUILD_QEMUX86_64_BIOS_GRUB_GPT	true
BUILD_QEMUX86_64_UEFI_GRUB	true
BUILD_VEXPRESS_QEMU	true
BUILD_VEXPRESS_QEMU_FLASH	true
BUILD_VEXPRESS_QEMU_UBOOT_UEFI_GRUB	true
INTEGRATION_REV	master
MENDER_BINARY_DELTA_REV	master
MENDER_CLIENT_SUBCOMPONENTS_REV	main
MENDER_CONFIGURE_MODULE_REV	master
MENDER_CONNECT_REV	master
MENDER_CONTAINER_MODULES_REV	main
MENDER_FLASH_REV	master
MENDER_REV	pull/1880/head
MONITOR_CLIENT_REV	master
RUN_INTEGRATION_TESTS	true
TEST_QEMUX86_64_BIOS_GRUB	true
TEST_QEMUX86_64_BIOS_GRUB_GPT	true
TEST_QEMUX86_64_UEFI_GRUB	true
TEST_VEXPRESS_QEMU	true
TEST_VEXPRESS_QEMU_FLASH	true
TEST_VEXPRESS_QEMU_UBOOT_UEFI_GRUB	true

mender-test-bot · 2026-01-23T14:43:48Z

Hello 😺 This PR contains changelog entries. Please, verify the need of backporting it to the following release branches:
5.0.x (release 3.8.x) - 🤖 🍒

michalkopczan · 2026-01-26T07:26:25Z

@mender-test-bot cherry-pick to:

5.0.x

mender-test-bot · 2026-01-26T07:26:36Z

Hi 😺
I did my very best, and this is the result of the cherry pick operation:

5.0.x ✔️ [Cherry 5.0.x]: fix: Prevent segfault by correctly handling dbus restarts in mender-update and mender-auth #1889

michalkopczan requested a review from vpodzime January 16, 2026 11:20

vpodzime reviewed Jan 19, 2026

View reviewed changes

Comment thread src/common/platform/dbus/asio_libdbus/dbus.cpp Outdated

Comment thread src/common/platform/dbus/asio_libdbus/dbus.cpp Outdated

Comment thread src/common/platform/dbus/asio_libdbus/dbus.cpp

Comment thread src/mender-update/daemon/states.cpp

michalkopczan force-pushed the MEN-9144-mender-client-segfaults-upon-dbus-shutdown branch from b7f17ee to ebfee33 Compare January 21, 2026 13:03

vpodzime approved these changes Jan 21, 2026

View reviewed changes

michalkopczan force-pushed the MEN-9144-mender-client-segfaults-upon-dbus-shutdown branch from ebfee33 to cfdde28 Compare January 22, 2026 10:17

michalkopczan added 2 commits January 23, 2026 11:59

michalkopczan force-pushed the MEN-9144-mender-client-segfaults-upon-dbus-shutdown branch from cfdde28 to 6aa4c77 Compare January 23, 2026 11:00

michalkopczan merged commit 7df5181 into mendersoftware:master Jan 23, 2026
14 checks passed

mender-test-bot mentioned this pull request Jan 26, 2026

[Cherry 5.0.x]: fix: Prevent segfault by correctly handling dbus restarts in mender-update and mender-auth #1889

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mender (MEN-9144-mender-client-segfaults-upon-dbus-shutdown)

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