Hello! This is an experimental semi-automated report about issues detected by Coverity from a scan of next-20221108 as part of the linux-next scan project: https://scan.coverity.com/projects/linux-next-weekly-scan You're getting this email because you were associated with the identified lines of code (noted below) that were touched by commits: Mon Nov 7 12:47:57 2022 +0100 e0a37003ff0b ("hw_random: use add_hwgenerator_randomness() for early entropy") Coverity reported the following: *** CID 1527234: Integer handling issues (SIGN_EXTENSION) drivers/char/hw_random/core.c:73 in add_early_randomness() 67 int bytes_read; 68 69 mutex_lock(&reading_mutex); 70 bytes_read = rng_get_data(rng, rng_fillbuf, 32, 0); 71 mutex_unlock(&reading_mutex); 72 if (bytes_read > 0) { vvv CID 1527234: Integer handling issues (SIGN_EXTENSION) vvv Suspicious implicit sign extension: "rng->quality" with type "unsigned short" (16 bits, unsigned) is promoted in "bytes_read * 8 * rng->quality / 1024" to type "int" (32 bits, signed), then sign-extended to type "unsigned long" (64 bits, unsigned). If "bytes_read * 8 * rng->quality / 1024" is greater than 0x7FFFFFFF, the upper bits of the result will all be 1. 73 size_t entropy = bytes_read * 8 * rng->quality / 1024; 74 add_hwgenerator_randomness(rng_fillbuf, bytes_read, entropy, false); 75 } 76 } 77 78 static inline void cleanup_rng(struct kref *kref) If this is a false positive, please let us know so we can mark it as such, or teach the Coverity rules to be smarter. If not, please make sure fixes get into linux-next. :) For patches fixing this, please include these lines (but double-check the "Fixes" first): Reported-by: coverity-bot <keescook+coverity-bot@xxxxxxxxxxxx> Addresses-Coverity-ID: 1527234 ("Integer handling issues") Fixes: e0a37003ff0b ("hw_random: use add_hwgenerator_randomness() for early entropy") Thanks for your attention! -- Coverity-bot
