diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2022-07-25 15:05:16 +0100 |
|---|---|---|
| committer | Alex Bennée <alex.bennee@linaro.org> | 2022-07-29 09:48:01 +0100 |
| commit | 9b1268f55ceb0d9390a051cad299b3021dfa9896 (patch) | |
| tree | b98e804a30e5ab6677c062284b1af70634de01ad /semihosting | |
| parent | fed49cdf6a721d76f9ac1cf76fd05b3fbd8b4892 (diff) | |
semihosting: Fix handling of buffer in TARGET_SYS_TMPNAM
The TARGET_SYS_TMPNAM implementation has two bugs spotted by
Coverity:
* confusion about whether 'len' has the length of the string
including or excluding the terminating NUL means we
lock_user() len bytes of memory but memcpy() len + 1 bytes
* In the error-exit cases we forget to free() the buffer
that asprintf() returned to us
Resolves: Coverity CID 1490285, 1490289
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220719121110.225657-5-peter.maydell@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220725140520.515340-10-alex.bennee@linaro.org>
Diffstat (limited to 'semihosting')
| -rw-r--r-- | semihosting/arm-compat-semi.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/semihosting/arm-compat-semi.c b/semihosting/arm-compat-semi.c index d12288fc80..e741674238 100644 --- a/semihosting/arm-compat-semi.c +++ b/semihosting/arm-compat-semi.c @@ -504,16 +504,25 @@ void do_common_semihosting(CPUState *cs) GET_ARG(1); GET_ARG(2); len = asprintf(&s, "/tmp/qemu-%x%02x", getpid(), (int)arg1 & 0xff); + if (len < 0) { + common_semi_set_ret(cs, -1); + break; + } + + /* Allow for trailing NUL */ + len++; /* Make sure there's enough space in the buffer */ - if (len < 0 || len >= arg2) { + if (len > arg2) { + free(s); common_semi_set_ret(cs, -1); break; } p = lock_user(VERIFY_WRITE, arg0, len, 0); if (!p) { + free(s); goto do_fault; } - memcpy(p, s, len + 1); + memcpy(p, s, len); unlock_user(p, arg0, len); free(s); common_semi_set_ret(cs, 0); |