diff options
Diffstat (limited to 'meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/CVE-2024-26602.patch')
| -rw-r--r-- | meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/CVE-2024-26602.patch | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/CVE-2024-26602.patch b/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/CVE-2024-26602.patch new file mode 100644 index 000000000..b9f68cca6 --- /dev/null +++ b/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/CVE-2024-26602.patch @@ -0,0 +1,89 @@ +From 2441a64070b85c14eecc3728cc87e883f953f265 Mon Sep 17 00:00:00 2001 +From: Linus Torvalds <torvalds@linuxfoundation.org> +Date: Sun, 4 Feb 2024 15:25:12 +0000 +Subject: sched/membarrier: reduce the ability to hammer on sys_membarrier + +commit 944d5fe50f3f03daacfea16300e656a1691c4a23 upstream. + +On some systems, sys_membarrier can be very expensive, causing overall +slowdowns for everything. So put a lock on the path in order to +serialize the accesses to prevent the ability for this to be called at +too high of a frequency and saturate the machine. + +Reviewed-and-tested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> +Acked-by: Borislav Petkov <bp@alien8.de> +Fixes: 22e4ebb97582 ("membarrier: Provide expedited private command") +Fixes: c5f58bd58f43 ("membarrier: Provide GLOBAL_EXPEDITED command") +Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> +[ converted to explicit mutex_*() calls - cleanup.h is not in this stable + branch - gregkh ] +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + kernel/sched/membarrier.c | 9 +++++++++ + 1 file changed, 9 insertions(+) + +diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c +index b5add64d9698..0b5e3e520bf6 100644 +--- a/kernel/sched/membarrier.c ++++ b/kernel/sched/membarrier.c +@@ -161,6 +161,8 @@ + | MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED \ + | MEMBARRIER_PRIVATE_EXPEDITED_SYNC_CORE_BITMASK) + ++static DEFINE_MUTEX(membarrier_ipi_mutex); ++ + static void ipi_mb(void *info) + { + smp_mb(); /* IPIs should be serializing but paranoid. */ +@@ -258,6 +260,7 @@ static int membarrier_global_expedited(void) + if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) + return -ENOMEM; + ++ mutex_lock(&membarrier_ipi_mutex); + cpus_read_lock(); + rcu_read_lock(); + for_each_online_cpu(cpu) { +@@ -303,6 +306,8 @@ static int membarrier_global_expedited(void) + * rq->curr modification in scheduler. + */ + smp_mb(); /* exit from system call is not a mb */ ++ mutex_unlock(&membarrier_ipi_mutex); ++ + return 0; + } + +@@ -346,6 +351,7 @@ static int membarrier_private_expedited(int flags, int cpu_id) + if (cpu_id < 0 && !zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) + return -ENOMEM; + ++ mutex_lock(&membarrier_ipi_mutex); + cpus_read_lock(); + + if (cpu_id >= 0) { +@@ -418,6 +424,7 @@ static int membarrier_private_expedited(int flags, int cpu_id) + * rq->curr modification in scheduler. + */ + smp_mb(); /* exit from system call is not a mb */ ++ mutex_unlock(&membarrier_ipi_mutex); + + return 0; + } +@@ -459,6 +466,7 @@ static int sync_runqueues_membarrier_state(struct mm_struct *mm) + * between threads which are users of @mm has its membarrier state + * updated. + */ ++ mutex_lock(&membarrier_ipi_mutex); + cpus_read_lock(); + rcu_read_lock(); + for_each_online_cpu(cpu) { +@@ -475,6 +483,7 @@ static int sync_runqueues_membarrier_state(struct mm_struct *mm) + + free_cpumask_var(tmpmask); + cpus_read_unlock(); ++ mutex_unlock(&membarrier_ipi_mutex); + + return 0; + } +-- +2.25.1 + |