From f6421555dbd7cb3d4d70b69f33f998aaeca1e3b5 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Mon, 15 Jan 2024 20:15:46 +0000 Subject: [PATCH] arm64/sme: Always exit sme_alloc() early with existing storage commit dc7eb8755797ed41a0d1b5c0c39df3c8f401b3d9 upstream. When sme_alloc() is called with existing storage and we are not flushing we will always allocate new storage, both leaking the existing storage and corrupting the state. Fix this by separating the checks for flushing and for existing storage as we do for SVE. Callers that reallocate (eg, due to changing the vector length) should call sme_free() themselves. Fixes: 5d0a8d2fba50 ("arm64/ptrace: Ensure that SME is set up for target when writing SSVE state") Signed-off-by: Mark Brown Cc: Link: https://lore.kernel.org/r/20240115-arm64-sme-flush-v1-1-7472bd3459b7@kernel.org Signed-off-by: Will Deacon Signed-off-by: Zhaoyang Li Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/fpsimd.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 47425311acc5..b3e101a7d04f 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1259,8 +1259,10 @@ void fpsimd_release_task(struct task_struct *dead_task) */ void sme_alloc(struct task_struct *task, bool flush) { - if (task->thread.za_state && flush) { - memset(task->thread.za_state, 0, za_state_size(task)); + if (task->thread.za_state) { + if (flush) + memset(task->thread.za_state, 0, + za_state_size(task)); return; }