4.17-stable review patch. If anyone has any objections, please let me know.
------------------ From: Mauricio Vasquez B <[email protected]> [ Upstream commit ed2b82c03dc187018307c7c6bf9299705f3db383 ] Decrement the number of elements in the map in case the allocation of a new node fails. Fixes: 6c9059817432 ("bpf: pre-allocate hash map elements") Signed-off-by: Mauricio Vasquez B <[email protected]> Acked-by: Alexei Starovoitov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- kernel/bpf/hashtab.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -743,13 +743,15 @@ static struct htab_elem *alloc_htab_elem * old element will be freed immediately. * Otherwise return an error */ - atomic_dec(&htab->count); - return ERR_PTR(-E2BIG); + l_new = ERR_PTR(-E2BIG); + goto dec_count; } l_new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN, htab->map.numa_node); - if (!l_new) - return ERR_PTR(-ENOMEM); + if (!l_new) { + l_new = ERR_PTR(-ENOMEM); + goto dec_count; + } } memcpy(l_new->key, key, key_size); @@ -762,7 +764,8 @@ static struct htab_elem *alloc_htab_elem GFP_ATOMIC | __GFP_NOWARN); if (!pptr) { kfree(l_new); - return ERR_PTR(-ENOMEM); + l_new = ERR_PTR(-ENOMEM); + goto dec_count; } } @@ -776,6 +779,9 @@ static struct htab_elem *alloc_htab_elem l_new->hash = hash; return l_new; +dec_count: + atomic_dec(&htab->count); + return l_new; } static int check_flags(struct bpf_htab *htab, struct htab_elem *l_old,
