From: Mark Brown broonie@kernel.org

mainline inclusion from mainline-v6.8-rc1 commit dc7eb8755797ed41a0d1b5c0c39df3c8f401b3d9 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IAF0D0

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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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 Conflicts: arch/arm64/kernel/fpsimd.c [Due to ce514000da4f ("arm64/sme: Rename za_state to sme_state") didn't backport to 5.10, this patch rename za_state to sme_state, fix this conflicts.] Signed-off-by: Lin Yujun linyujun809@huawei.com --- 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 c2489a72b0b9..190c2f154c1c 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1219,8 +1219,10 @@ 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, + sme_state_size(task)); return; }