Re: [PATCH] objtool: prevent memory leak in error paths
Em Thu, Apr 15, 2021 at 09:24:41AM +0200, Peter Zijlstra escreveu: > On Wed, Apr 14, 2021 at 11:47:09AM +0300, Dan Carpenter wrote: > > On Wed, Apr 14, 2021 at 01:45:11AM +0500, Muhammad Usama Anjum wrote: > > > Memory allocated by sym and sym->name isn't being freed if some error > > > occurs in elf_create_undef_symbol(). Free the sym and sym->name if error > > > is detected before returning NULL. > > > > > > Addresses-Coverity: ("Prevent memory leak") > > > Fixes: 2f2f7e47f052 ("objtool: Add elf_create_undef_symbol()") > > > Signed-off-by: Muhammad Usama Anjum > > > --- > > > Only build has been tested. > > > > > > > Just ignore leaks from the tools/ directory. These things run and then > > exit and all the memory is freed. #OldSchoolGarbageCollector > > Mostly true; but I suspect tools/perf might care, it has some longer > running things in. Yes, and now we have 'perf daemon' that is long running. - Arnaldo
Re: [PATCH] objtool: prevent memory leak in error paths
On Wed, Apr 14, 2021 at 11:47:09AM +0300, Dan Carpenter wrote: > On Wed, Apr 14, 2021 at 01:45:11AM +0500, Muhammad Usama Anjum wrote: > > Memory allocated by sym and sym->name isn't being freed if some error > > occurs in elf_create_undef_symbol(). Free the sym and sym->name if error > > is detected before returning NULL. > > > > Addresses-Coverity: ("Prevent memory leak") > > Fixes: 2f2f7e47f052 ("objtool: Add elf_create_undef_symbol()") > > Signed-off-by: Muhammad Usama Anjum > > --- > > Only build has been tested. > > > > Just ignore leaks from the tools/ directory. These things run and then > exit and all the memory is freed. #OldSchoolGarbageCollector Mostly true; but I suspect tools/perf might care, it has some longer running things in.
Re: [PATCH] objtool: prevent memory leak in error paths
On Wed, Apr 14, 2021 at 01:45:11AM +0500, Muhammad Usama Anjum wrote: > Memory allocated by sym and sym->name isn't being freed if some error > occurs in elf_create_undef_symbol(). Free the sym and sym->name if error > is detected before returning NULL. > > Addresses-Coverity: ("Prevent memory leak") > Fixes: 2f2f7e47f052 ("objtool: Add elf_create_undef_symbol()") > Signed-off-by: Muhammad Usama Anjum > --- > Only build has been tested. > Just ignore leaks from the tools/ directory. These things run and then exit and all the memory is freed. #OldSchoolGarbageCollector regards, dan carpenter
Re: [PATCH] objtool: prevent memory leak in error paths
On Wed, Apr 14, 2021 at 01:45:11AM +0500, Muhammad Usama Anjum wrote: > Memory allocated by sym and sym->name isn't being freed if some error > occurs in elf_create_undef_symbol(). Free the sym and sym->name if error > is detected before returning NULL. > > Addresses-Coverity: ("Prevent memory leak") -EDONTCARE, objtool is single-shot by design, on error we quit, which frees all memory. Please exclude all of objtool from this class of problems in your Coverity thing.
[PATCH] objtool: prevent memory leak in error paths
Memory allocated by sym and sym->name isn't being freed if some error occurs in elf_create_undef_symbol(). Free the sym and sym->name if error is detected before returning NULL. Addresses-Coverity: ("Prevent memory leak") Fixes: 2f2f7e47f052 ("objtool: Add elf_create_undef_symbol()") Signed-off-by: Muhammad Usama Anjum --- Only build has been tested. tools/objtool/elf.c | 12 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index d08f5f3670f8..17ee265a6c6b 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -733,7 +733,7 @@ struct symbol *elf_create_undef_symbol(struct elf *elf, const char *name) sym->sym.st_name = elf_add_string(elf, NULL, sym->name); if (sym->sym.st_name == -1) - return NULL; + goto err; sym->sym.st_info = GELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); // st_other 0 @@ -744,19 +744,19 @@ struct symbol *elf_create_undef_symbol(struct elf *elf, const char *name) symtab = find_section_by_name(elf, ".symtab"); if (!symtab) { WARN("can't find .symtab"); - return NULL; + goto err; } s = elf_getscn(elf->elf, symtab->idx); if (!s) { WARN_ELF("elf_getscn"); - return NULL; + goto err; } data = elf_newdata(s); if (!data) { WARN_ELF("elf_newdata"); - return NULL; + goto err; } data->d_buf = >sym; @@ -773,6 +773,10 @@ struct symbol *elf_create_undef_symbol(struct elf *elf, const char *name) elf_add_symbol(elf, sym); return sym; +err: + free(sym->name); + free(sym); + return NULL; } struct section *elf_create_section(struct elf *elf, const char *name, -- 2.25.1