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authorJakub Kicinski <kuba@kernel.org>2021-06-26 01:16:12 +0300
committerDaniel Borkmann <daniel@iogearbox.net>2021-06-29 00:07:59 +0300
commita78cae2476812cecaa4a33d0086bbb53986906bc (patch)
treee94ee657d160e397cc33a6e0cf8ce76b7d3d851d /net
parentccff81e1d028bbbf8573d3364a87542386c707bf (diff)
downloadlinux-a78cae2476812cecaa4a33d0086bbb53986906bc.tar.xz
xdp: Move the rxq_info.mem clearing to unreg_mem_model()
xdp_rxq_info_unreg() implicitly calls xdp_rxq_info_unreg_mem_model(). This may well be confusing to the driver authors, and lead to double free if they call xdp_rxq_info_unreg_mem_model() before xdp_rxq_info_unreg() (when mem model type == MEM_TYPE_PAGE_POOL). In fact error path of mvpp2_rxq_init() seems to currently do exactly that. The double free will result in refcount underflow in page_pool_destroy(). Make the interface a little more programmer friendly by clearing type and id so that xdp_rxq_info_unreg_mem_model() can be called multiple times. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210625221612.2637086-1-kuba@kernel.org
Diffstat (limited to 'net')
-rw-r--r--net/core/xdp.c11
1 files changed, 6 insertions, 5 deletions
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 725d20f1b100..cc92ccb38432 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -113,8 +113,13 @@ static void mem_allocator_disconnect(void *allocator)
void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq)
{
struct xdp_mem_allocator *xa;
+ int type = xdp_rxq->mem.type;
int id = xdp_rxq->mem.id;
+ /* Reset mem info to defaults */
+ xdp_rxq->mem.id = 0;
+ xdp_rxq->mem.type = 0;
+
if (xdp_rxq->reg_state != REG_STATE_REGISTERED) {
WARN(1, "Missing register, driver bug");
return;
@@ -123,7 +128,7 @@ void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq)
if (id == 0)
return;
- if (xdp_rxq->mem.type == MEM_TYPE_PAGE_POOL) {
+ if (type == MEM_TYPE_PAGE_POOL) {
rcu_read_lock();
xa = rhashtable_lookup(mem_id_ht, &id, mem_id_rht_params);
page_pool_destroy(xa->page_pool);
@@ -144,10 +149,6 @@ void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq)
xdp_rxq->reg_state = REG_STATE_UNREGISTERED;
xdp_rxq->dev = NULL;
-
- /* Reset mem info to defaults */
- xdp_rxq->mem.id = 0;
- xdp_rxq->mem.type = 0;
}
EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg);