timers/migration: Prevent out of bounds access on failure

When tmigr_setup_groups() fails the level 0 group allocation, then the
cleanup derefences index -1 of the local stack array.

Prevent this by checking the loop condition first.

Fixes: 7ee9887703 ("timers: Implement the hierarchical pull model")
Signed-off-by: Levi Yun <ppbuk5246@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Link: https://lore.kernel.org/r/20240506041059.86877-1-ppbuk5246@gmail.com
This commit is contained in:
Levi Yun 2024-05-06 05:10:59 +01:00 committed by Thomas Gleixner
parent dd5a440a31
commit d7ad05c86e

View File

@ -1596,7 +1596,7 @@ static int tmigr_setup_groups(unsigned int cpu, unsigned int node)
} while (i < tmigr_hierarchy_levels);
do {
while (i > 0) {
group = stack[--i];
if (err < 0) {
@ -1645,7 +1645,7 @@ static int tmigr_setup_groups(unsigned int cpu, unsigned int node)
tmigr_connect_child_parent(child, group);
}
}
} while (i > 0);
}
kfree(stack);