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authorDavid Rientjes <rientjes@google.com>2022-12-31 01:18:46 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-03-11 18:39:20 +0300
commit4c33e01fe1d294b46c0212f213b8553e53604375 (patch)
tree2845ad019e74fec7fc925fc0610873e9abc4a220 /drivers/crypto
parent4c5300f6f5e18b11c02a92f136e69b98fddba15e (diff)
downloadlinux-4c33e01fe1d294b46c0212f213b8553e53604375.tar.xz
crypto: ccp - Avoid page allocation failure warning for SEV_GET_ID2
[ Upstream commit 91dfd98216d817ec5f1c55890bacb7b4fe9b068a ] For SEV_GET_ID2, the user provided length does not have a specified limitation because the length of the ID may change in the future. The kernel memory allocation, however, is implicitly limited to 4MB on x86 by the page allocator, otherwise the kzalloc() will fail. When this happens, it is best not to spam the kernel log with the warning. Simply fail the allocation and return ENOMEM to the user. Fixes: d6112ea0cb34 ("crypto: ccp - introduce SEV_GET_ID2 command") Reported-by: Andy Nguyen <theflow@google.com> Reported-by: Peter Gonda <pgonda@google.com> Suggested-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/crypto')
-rw-r--r--drivers/crypto/ccp/sev-dev.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 6edd938ce6ac..e70ae98de118 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -631,7 +631,14 @@ static int sev_ioctl_do_get_id2(struct sev_issue_cmd *argp)
input_address = (void __user *)input.address;
if (input.address && input.length) {
- id_blob = kzalloc(input.length, GFP_KERNEL);
+ /*
+ * The length of the ID shouldn't be assumed by software since
+ * it may change in the future. The allocation size is limited
+ * to 1 << (PAGE_SHIFT + MAX_ORDER - 1) by the page allocator.
+ * If the allocation fails, simply return ENOMEM rather than
+ * warning in the kernel log.
+ */
+ id_blob = kzalloc(input.length, GFP_KERNEL | __GFP_NOWARN);
if (!id_blob)
return -ENOMEM;