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| author | Sean Christopherson <seanjc@google.com> | 2021-04-06 15:49:47 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-04-21 12:20:06 -0400 |
| commit | d5760dee127bf6f390b05e747369d7c37ae1a7b8 (patch) | |
| tree | 5adee8934b616ccdf04acf7467f045465ecbfab5 /drivers/crypto | |
| parent | 74c1f1366eb7714b8b211554f6c5cee315ff3fbc (diff) | |
| download | linux-d5760dee127bf6f390b05e747369d7c37ae1a7b8.tar.gz linux-d5760dee127bf6f390b05e747369d7c37ae1a7b8.tar.xz | |
crypto: ccp: Reject SEV commands with mismatching command buffer
WARN on and reject SEV commands that provide a valid data pointer, but do
not have a known, non-zero length. And conversely, reject commands that
take a command buffer but none is provided (data is null).
Aside from sanity checking input, disallowing a non-null pointer without
a non-zero size will allow a future patch to cleanly handle vmalloc'd
data by copying the data to an internal __pa() friendly buffer.
Note, this also effectively prevents callers from using commands that
have a non-zero length and are not known to the kernel. This is not an
explicit goal, but arguably the side effect is a good thing from the
kernel's perspective.
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210406224952.4177376-4-seanjc@google.com>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'drivers/crypto')
| -rw-r--r-- | drivers/crypto/ccp/sev-dev.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index f53086cc7b92..fb08783f532d 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -142,6 +142,7 @@ static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret) struct sev_device *sev; unsigned int phys_lsb, phys_msb; unsigned int reg, ret = 0; + int buf_len; if (!psp || !psp->sev_data) return -ENODEV; @@ -151,6 +152,10 @@ static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret) sev = psp->sev_data; + buf_len = sev_cmd_buffer_len(cmd); + if (WARN_ON_ONCE(!data != !buf_len)) + return -EINVAL; + if (data && WARN_ON_ONCE(!virt_addr_valid(data))) return -EINVAL; @@ -162,7 +167,7 @@ static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret) cmd, phys_msb, phys_lsb, psp_timeout); print_hex_dump_debug("(in): ", DUMP_PREFIX_OFFSET, 16, 2, data, - sev_cmd_buffer_len(cmd), false); + buf_len, false); iowrite32(phys_lsb, sev->io_regs + sev->vdata->cmdbuff_addr_lo_reg); iowrite32(phys_msb, sev->io_regs + sev->vdata->cmdbuff_addr_hi_reg); @@ -198,7 +203,7 @@ static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret) } print_hex_dump_debug("(out): ", DUMP_PREFIX_OFFSET, 16, 2, data, - sev_cmd_buffer_len(cmd), false); + buf_len, false); return ret; } |