Re: [PATCH 1/2] arm64/pageattr: Propagate return value from __change_memory_common
From: Ryan Roberts <ryan.roberts@arm.com>
Date: 2025-11-13 11:55:51
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On 12/11/2025 06:27, Dev Jain wrote:
The rodata=on security measure requires that any code path which does
vmalloc -> set_memory_ro/set_memory_rox must protect the linear map alias
too. Therefore, if such a call fails, we must abort set_memory_* and caller
must take appropriate action; currently we are suppressing the error, and
there is a real chance of such an error arising post commit a166563e7ec3
("arm64: mm: support large block mapping when rodata=full"). Therefore,
propagate any error to the caller.
Fixes: a166563e7ec3 ("arm64: mm: support large block mapping when rodata=full")
Signed-off-by: Dev Jain <dev.jain@arm.com>Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> It would be good to get this into v6.18 I guess? Although I think this will conflict with a patch from Yang that makes this work with a partial vm area range - But I think that one will only go to v6.19. Thanks, Ryan
quoted hunk ↗ jump to hunk
--- v1 of this patch: https://lore.kernel.org/all/20251103061306.82034-1-dev.jain@arm.com/ (local) I have dropped stable since no real chance of failure was there. arch/arm64/mm/pageattr.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index 5135f2d66958..b4ea86cd3a71 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c@@ -148,6 +148,7 @@ static int change_memory_common(unsigned long addr, int numpages, unsigned long size = PAGE_SIZE * numpages; unsigned long end = start + size; struct vm_struct *area; + int ret; int i; if (!PAGE_ALIGNED(addr)) {@@ -185,8 +186,10 @@ static int change_memory_common(unsigned long addr, int numpages, if (rodata_full && (pgprot_val(set_mask) == PTE_RDONLY || pgprot_val(clear_mask) == PTE_RDONLY)) { for (i = 0; i < area->nr_pages; i++) { - __change_memory_common((u64)page_address(area->pages[i]), + ret = __change_memory_common((u64)page_address(area->pages[i]), PAGE_SIZE, set_mask, clear_mask); + if (ret) + return ret; } }