6.1-stable review patch. If anyone has any objections, please let me know.
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From: Mark Brown broonie@kernel.org
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 broonie@kernel.org Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240115-arm64-sme-flush-v1-1-7472bd3459b7@kernel.... Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Zhaoyang Li lizy04@hust.edu.cn Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/kernel/fpsimd.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1259,8 +1259,10 @@ void fpsimd_release_task(struct task_str */ 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; }