diff options
| author | Denys Vlasenko <vda.linux@googlemail.com> | 2012-09-26 11:34:50 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-07 08:35:55 -0700 |
| commit | a4c1d25f27206a872ca0261bffdf3509d4ef6fc8 (patch) | |
| tree | 5ea4d8643689ef9815099fa4cb9a7a9994594939 | |
| parent | d4663b9b9f18c0c818f9632fc4bf194521c4fe76 (diff) | |
| download | lwn-a4c1d25f27206a872ca0261bffdf3509d4ef6fc8.tar.gz lwn-a4c1d25f27206a872ca0261bffdf3509d4ef6fc8.zip | |
coredump: prevent double-free on an error path in core dumper
commit f34f9d186df35e5c39163444c43b4fc6255e39c5 upstream.
In !CORE_DUMP_USE_REGSET case, if elf_note_info_init fails to allocate
memory for info->fields, it frees already allocated stuff and returns
error to its caller, fill_note_info. Which in turn returns error to its
caller, elf_core_dump. Which jumps to cleanup label and calls
free_note_info, which will happily try to free all info->fields again.
BOOM.
This is the fix.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Venu Byravarasu <vbyravarasu@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/binfmt_elf.c | 19 |
1 files changed, 4 insertions, 15 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 1b52956afe33..0225fddf49b7 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1696,30 +1696,19 @@ static int elf_note_info_init(struct elf_note_info *info) return 0; info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL); if (!info->psinfo) - goto notes_free; + return 0; info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL); if (!info->prstatus) - goto psinfo_free; + return 0; info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL); if (!info->fpu) - goto prstatus_free; + return 0; #ifdef ELF_CORE_COPY_XFPREGS info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL); if (!info->xfpu) - goto fpu_free; + return 0; #endif return 1; -#ifdef ELF_CORE_COPY_XFPREGS - fpu_free: - kfree(info->fpu); -#endif - prstatus_free: - kfree(info->prstatus); - psinfo_free: - kfree(info->psinfo); - notes_free: - kfree(info->notes); - return 0; } static int fill_note_info(struct elfhdr *elf, int phdrs, |