Commit f34f9d18 authored by Denys Vlasenko's avatar Denys Vlasenko Committed by Al Viro

coredump: prevent double-free on an error path in core dumper

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: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarDenys Vlasenko <vda.linux@googlemail.com>
Cc: Venu Byravarasu <vbyravarasu@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 260ef311
......@@ -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,
......
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