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| author | Alexey Kardashevskiy <aik@amd.com> | 2025-06-17 12:43:54 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-15 13:13:53 +0300 |
| commit | 155c1d4c49079f24a4b5b0c51ceb94e73cacd7ac (patch) | |
| tree | 25758dc9018d2e0ba7ba1be8ad8f839c4d1571a7 | |
| parent | 88d4191073a54b9573c985e19abad278a314268a (diff) | |
| download | linux-155c1d4c49079f24a4b5b0c51ceb94e73cacd7ac.tar.xz | |
crypto: ccp - Fix locking on alloc failure handling
[ 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>
| -rw-r--r-- | drivers/crypto/ccp/sev-dev.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index af018afd9cd7..4d072c084d7b 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -424,7 +424,7 @@ cleanup: 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; |