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| author | Eugene Syromiatnikov <[email protected]> | 2025-08-29 10:02:39 +0200 |
|---|---|---|
| committer | Tomas Mraz <[email protected]> | 2025-09-09 20:22:30 +0200 |
| commit | 5473955b3015d3ca49c040e5cf6ab9cd6bcdc1c8 (patch) | |
| tree | 78446faca6fa78fef8d0c182c3830f4c9a4ff312 | |
| parent | Make the Unix build process more repeatable (diff) | |
| download | openssl-5473955b3015d3ca49c040e5cf6ab9cd6bcdc1c8.tar.gz openssl-5473955b3015d3ca49c040e5cf6ab9cd6bcdc1c8.zip | |
crypto/rand/randfile.c: avoid signed integer overflow in RAND_load_file
If a file supplied to RAND_load_file is too big (more than INT_MAX bytes),
it is possible to trigger a signer integer overflow during ret calculation.
Avoid it by returning early when we are about to hit it on the next
iteration.
Reported-by: Liu-Ermeng <[email protected]>
Resolves: https://github.com/openssl/openssl/issues/28375
Signed-off-by: Eugene Syromiatnikov <[email protected]>
Reviewed-by: Paul Dale <[email protected]>
Reviewed-by: Saša Nedvědický <[email protected]>
Reviewed-by: Tomas Mraz <[email protected]>
(Merged from https://github.com/openssl/openssl/pull/28379)
(cherry picked from commit 35db6a15d436aa4d981ebcd581eded55fc8c8fb6)
| -rw-r--r-- | crypto/rand/randfile.c | 4 | ||||
| -rw-r--r-- | doc/man3/RAND_load_file.pod | 2 |
2 files changed, 6 insertions, 0 deletions
diff --git a/crypto/rand/randfile.c b/crypto/rand/randfile.c index 9337b36dc8b..adfdb0f414e 100644 --- a/crypto/rand/randfile.c +++ b/crypto/rand/randfile.c @@ -167,6 +167,10 @@ int RAND_load_file(const char *file, long bytes) /* If given a bytecount, and we did it, break. */ if (bytes > 0 && (bytes -= i) <= 0) break; + + /* We can hit a signed integer overflow on the next iteration */ + if (ret > INT_MAX - RAND_LOAD_BUF_SIZE) + break; } OPENSSL_cleanse(buf, sizeof(buf)); diff --git a/doc/man3/RAND_load_file.pod b/doc/man3/RAND_load_file.pod index baca54cb3c8..fd00bf883d4 100644 --- a/doc/man3/RAND_load_file.pod +++ b/doc/man3/RAND_load_file.pod @@ -20,6 +20,8 @@ RAND_load_file() reads a number of bytes from file B<filename> and adds them to the PRNG. If B<max_bytes> is nonnegative, up to B<max_bytes> are read; if B<max_bytes> is -1, the complete file is read. +RAND_load_file() can read less than the complete file or the requested number +of bytes if it doesn't fit in the return value type. Do not load the same file multiple times unless its contents have been updated by RAND_write_file() between reads. Also, note that B<filename> should be adequately protected so that an |