Re: [uclibc-ng-devel] [PATCH] malloc: Add missing locks for some paths (valloc/memalign/posix_memalign)

Hello, Do you have a small test case that could reproduce the issue that could be added to uClibc-ng testsuite? Thanks! Yann On 9/25/19 9:59 AM, Kjetil Oftedal wrote: > The internal heap structures were not protected properly in > memalign(). If multiple threads were concurrently allocating memory and > one of them were requesting aligned memory via valloc,memalign or > posix_memalign the internal heap data structures could be corrupted. > > Signed-off-by: Kjetil Oftedal &lt;oftedal(a)gmail.com&gt; > --- > libc/stdlib/malloc/memalign.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/libc/stdlib/malloc/memalign.c b/libc/stdlib/malloc/memalign.c > index 74d5dbd..0d3de67 100644 > --- a/libc/stdlib/malloc/memalign.c > +++ b/libc/stdlib/malloc/memalign.c > @@ -77,7 +77,9 @@ memalign (size_t alignment, size_t size) > init_size = addr - tot_addr; > } > > + __heap_lock (&__malloc_heap_lock); > __heap_free (heap, base, init_size); > + __heap_unlock (&__malloc_heap_lock); > > /* Remember that we've freed the initial part of MEM. */ > base += init_size; > @@ -85,9 +87,11 @@ memalign (size_t alignment, size_t size) > > /* Return the end part of MEM to the heap, unless it's too small. */ > end_addr = addr + size; > - if (end_addr + MALLOC_REALLOC_MIN_FREE_SIZE < tot_end_addr) > + if (end_addr + MALLOC_REALLOC_MIN_FREE_SIZE < tot_end_addr) { > + __heap_lock (&__malloc_heap_lock); > __heap_free (heap, (void *)end_addr, tot_end_addr - end_addr); > - else > + __heap_unlock (&__malloc_heap_lock); > + } else > /* We didn't free the end, so include it in the size. */ > end_addr = tot_end_addr; >