iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mm: don't allow oversized kvmalloc() calls

Browse Source 
commit 7661809d493b426e979f39ab512e3adf41fbcc69 upstream.

'kvmalloc()' is a convenience function for people who want to do a
kmalloc() but fall back on vmalloc() if there aren't enough physically
contiguous pages, or if the allocation is larger than what kmalloc()
supports.

However, let's make sure it doesn't get _too_ easy to do crazy things
with it.  In particular, don't allow big allocations that could be due
to integer overflow or underflow.  So make sure the allocation size fits
in an 'int', to protect against trivial integer conversion issues.

Acked-by: Willy Tarreau <w@1wt.eu>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Linus Torvalds 2021-07-14 09:45:49 -07:00 committed by Greg Kroah-Hartman
parent da5b8b9319
commit 57a269a1b1
1 changed files with 4 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
mm/util.c
View File

@ -581,6 +581,10 @@ void *kvmalloc_node(size_t size, gfp_t flags, int node)
if (ret || size <= PAGE_SIZE)
return ret;
/* Don't even allow crazy sizes */
if (WARN_ON_ONCE(size > INT_MAX))
return NULL;
return __vmalloc_node(size, 1, flags, node,
__builtin_return_address(0));
}