From 5bb88024409ef7bb53e5d42d35097a7a3157f764 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Sat, 29 Nov 2025 00:48:45 +0000 Subject: [PATCH] arm64/gcs: Flush the GCS locking state on exec commit 98a97bf41528ef738b06eb07ec2b2eb1cfde6ce6 upstream. When we exec a new task we forget to flush the set of locked GCS mode bits. Since we do flush the rest of the state this means that if GCS is locked the new task will be unable to enable GCS, it will be locked as being disabled. Add the expected flush. Fixes: fc84bc5378a8 ("arm64/gcs: Context switch GCS state for EL0") Cc: # 6.13.x Reported-by: Yury Khrustalev Signed-off-by: Mark Brown Tested-by: Yury Khrustalev Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/process.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index fba7ca102a8c..489554931231 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -292,6 +292,7 @@ static void flush_gcs(void) current->thread.gcs_base = 0; current->thread.gcs_size = 0; current->thread.gcs_el0_mode = 0; + current->thread.gcs_el0_locked = 0; write_sysreg_s(GCSCRE0_EL1_nTR, SYS_GCSCRE0_EL1); write_sysreg_s(0, SYS_GCSPR_EL0); }