| Message ID | 20241013131110.1706-1-esalomatkina@ispras.ru (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | sumversion: Fix a memory leak in get_src_version() | expand |
On Sun, Oct 13, 2024 at 10:11 PM Elena Salomatkina <esalomatkina@ispras.ru> wrote: > > strsep() modifies its first argument - buf. > If an error occurs in the parsing loop, an invalid pointer > will be passed to the free() function. > Make the pointer passed to free() match the return value of > read_text_file(). > > Found by Linux Verification Center (linuxtesting.org) with SVACE. > > Fixes: 9413e7640564 ("kbuild: split the second line of *.mod into *.usyms") > Signed-off-by: Elena Salomatkina <esalomatkina@ispras.ru> Thanks for spotting this. This is a bike-shed, but please use 'p' or 'pos' as the moving pointer and keep the 'buf'. This is consistent with the following functions: extract_crcs_for_object() mod_set_crcs() handle_white_list_exports() read_dump() parse_source_files() > --- > scripts/mod/sumversion.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/scripts/mod/sumversion.c b/scripts/mod/sumversion.c > index 6bf9caca0968..03774957d8b9 100644 > --- a/scripts/mod/sumversion.c > +++ b/scripts/mod/sumversion.c > @@ -385,7 +385,7 @@ static int parse_source_files(const char *objfile, struct md4_ctx *md) > /* Calc and record src checksum. */ > void get_src_version(const char *modname, char sum[], unsigned sumlen) > { > - char *buf; > + char *buf, *orig; > struct md4_ctx md; > char *fname; > char filelist[PATH_MAX + 1]; > @@ -393,7 +393,7 @@ void get_src_version(const char *modname, char sum[], unsigned sumlen) > /* objects for a module are listed in the first line of *.mod file. */ > snprintf(filelist, sizeof(filelist), "%s.mod", modname); > > - buf = read_text_file(filelist); > + orig = buf = read_text_file(filelist); > > md4_init(&md); > while ((fname = strsep(&buf, "\n"))) { > @@ -406,5 +406,5 @@ void get_src_version(const char *modname, char sum[], unsigned sumlen) > > md4_final_ascii(&md, sum, sumlen); > free: > - free(buf); > + free(orig); > } > -- > 2.33.0 > >
diff --git a/scripts/mod/sumversion.c b/scripts/mod/sumversion.c index 6bf9caca0968..03774957d8b9 100644 --- a/scripts/mod/sumversion.c +++ b/scripts/mod/sumversion.c @@ -385,7 +385,7 @@ static int parse_source_files(const char *objfile, struct md4_ctx *md) /* Calc and record src checksum. */ void get_src_version(const char *modname, char sum[], unsigned sumlen) { - char *buf; + char *buf, *orig; struct md4_ctx md; char *fname; char filelist[PATH_MAX + 1]; @@ -393,7 +393,7 @@ void get_src_version(const char *modname, char sum[], unsigned sumlen) /* objects for a module are listed in the first line of *.mod file. */ snprintf(filelist, sizeof(filelist), "%s.mod", modname); - buf = read_text_file(filelist); + orig = buf = read_text_file(filelist); md4_init(&md); while ((fname = strsep(&buf, "\n"))) { @@ -406,5 +406,5 @@ void get_src_version(const char *modname, char sum[], unsigned sumlen) md4_final_ascii(&md, sum, sumlen); free: - free(buf); + free(orig); }
strsep() modifies its first argument - buf. If an error occurs in the parsing loop, an invalid pointer will be passed to the free() function. Make the pointer passed to free() match the return value of read_text_file(). Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 9413e7640564 ("kbuild: split the second line of *.mod into *.usyms") Signed-off-by: Elena Salomatkina <esalomatkina@ispras.ru> --- scripts/mod/sumversion.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)