power: supply: sbs-battery: Fix use-after-free in power_supply_changed()

Browse source

[ Upstream commit 8d59cf3887 ]

Using the `devm_` variant for requesting IRQ _before_ the `devm_`
variant for allocating/registering the `power_supply` handle, means that
the `power_supply` handle will be deallocated/unregistered _before_ the
interrupt handler (since `devm_` naturally deallocates in reverse
allocation order). This means that during removal, there is a race
condition where an interrupt can fire just _after_ the `power_supply`
handle has been freed, *but* just _before_ the corresponding
unregistration of the IRQ handler has run.

This will lead to the IRQ handler calling `power_supply_changed()` with
a freed `power_supply` handle. Which usually crashes the system or
otherwise silently corrupts the memory...

Note that there is a similar situation which can also happen during
`probe()`; the possibility of an interrupt firing _before_ registering
the `power_supply` handle. This would then lead to the nasty situation
of using the `power_supply` handle *uninitialized* in
`power_supply_changed()`.

Fix this racy use-after-free by making sure the IRQ is requested _after_
the registration of the `power_supply` handle. Keep the old behavior of
just printing a warning in case of any failures during the IRQ request
and finishing the probe successfully.

Fixes: d2cec82c28 ("power: sbs-battery: Request threaded irq and fix dev callback cookie")
Signed-off-by: Waqar Hameed <waqar.hameed@axis.com>
Reviewed-by: Phil Reid <preid@electromag.com.au>
Link: https://patch.msgid.link/0ef896e002495e615157b482d18a437af19ddcd0.1766268280.git.waqar.hameed@axis.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

...

This commit is contained in:

Waqar Hameed 2025-12-20 23:36:02 +01:00 • committed by Greg Kroah-Hartman

parent 64e1515509

commit 861dda7a90

1 changed files with 18 additions and 18 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

36

drivers/power/supply/sbs-battery.c

View file