6.15-stable review patch. If anyone has any objections, please let me know.
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From: Alexey Kardashevskiy aik@amd.com
[ Upstream commit b4abeccb8d39db7d9b51cb0098d6458760b30a75 ]
The __snp_alloc_firmware_pages() helper allocates pages in the firmware state (alloc + rmpupdate). In case of failed rmpupdate, it tries reclaiming pages with already changed state. This requires calling the PSP firmware and since there is sev_cmd_mutex to guard such calls, the helper takes a "locked" parameter so specify if the lock needs to be held.
Most calls happen from snp_alloc_firmware_page() which executes without the lock. However
commit 24512afa4336 ("crypto: ccp: Handle the legacy TMR allocation when SNP is enabled")
switched sev_fw_alloc() from alloc_pages() (which does not call the PSP) to __snp_alloc_firmware_pages() (which does) but did not account for the fact that sev_fw_alloc() is called from __sev_platform_init_locked() (via __sev_platform_init_handle_tmr()) and executes with the lock held.
Add a "locked" parameter to __snp_alloc_firmware_pages(). Make sev_fw_alloc() use the new parameter to prevent potential deadlock in rmp_mark_pages_firmware() if rmpupdate() failed.
Fixes: 24512afa4336 ("crypto: ccp: Handle the legacy TMR allocation when SNP is enabled") Signed-off-by: Alexey Kardashevskiy aik@amd.com Reviewed-by: Tom Lendacky thomas.lendacky@amd.com Reviewed-by: Pratik R. Sampat prsampat@amd.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/crypto/ccp/sev-dev.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index 2e87ca0e292a..4d790837af22 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -424,7 +424,7 @@ static int rmp_mark_pages_firmware(unsigned long paddr, unsigned int npages, boo return rc; }
-static struct page *__snp_alloc_firmware_pages(gfp_t gfp_mask, int order) +static struct page *__snp_alloc_firmware_pages(gfp_t gfp_mask, int order, bool locked) { unsigned long npages = 1ul << order, paddr; struct sev_device *sev; @@ -443,7 +443,7 @@ static struct page *__snp_alloc_firmware_pages(gfp_t gfp_mask, int order) return page;
paddr = __pa((unsigned long)page_address(page)); - if (rmp_mark_pages_firmware(paddr, npages, false)) + if (rmp_mark_pages_firmware(paddr, npages, locked)) return NULL;
return page; @@ -453,7 +453,7 @@ void *snp_alloc_firmware_page(gfp_t gfp_mask) { struct page *page;
- page = __snp_alloc_firmware_pages(gfp_mask, 0); + page = __snp_alloc_firmware_pages(gfp_mask, 0, false);
return page ? page_address(page) : NULL; } @@ -488,7 +488,7 @@ static void *sev_fw_alloc(unsigned long len) { struct page *page;
- page = __snp_alloc_firmware_pages(GFP_KERNEL, get_order(len)); + page = __snp_alloc_firmware_pages(GFP_KERNEL, get_order(len), true); if (!page) return NULL;