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| author | Konrad Beckmann <konrad.beckmann@gmail.com> | 2018-11-07 22:51:45 +0300 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2018-11-17 00:52:01 +0300 |
| commit | f1c85688ab13f154ebe1b1480def233a22e7f66b (patch) | |
| tree | c442e39843d945fb0df01ce2af6e431fc718a402 | |
| parent | ad5fbc6e8858d0f57a0712f7dba2c710aed9a43c (diff) | |
| download | u-boot-f1c85688ab13f154ebe1b1480def233a22e7f66b.tar.xz | |
image-sig: Ensure that hashed-nodes is null-terminated
A specially crafted FIT image leads to memory corruption in the stack
when using the verified boot feature. The function fit_config_check_sig
has a logic error that makes it possible to write past the end of the
stack allocated array node_inc. This could potentially be used to bypass
the signature check when using verified boot.
This change ensures that the number of strings is correct when counted.
Signed-off-by: Konrad Beckmann <konrad.beckmann@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
| -rw-r--r-- | common/image-sig.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/common/image-sig.c b/common/image-sig.c index 5a269d3289..5d860e1266 100644 --- a/common/image-sig.c +++ b/common/image-sig.c @@ -334,6 +334,11 @@ int fit_config_check_sig(const void *fit, int noffset, int required_keynode, return -1; } + if (prop && prop_len > 0 && prop[prop_len - 1] != '\0') { + *err_msgp = "hashed-nodes property must be null-terminated"; + return -1; + } + /* Add a sanity check here since we are using the stack */ if (count > IMAGE_MAX_HASHED_NODES) { *err_msgp = "Number of hashed nodes exceeds maximum"; |