diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2021-06-25 15:16:12 -0700 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-06-28 23:07:59 +0200 |
| commit | a78cae2476812cecaa4a33d0086bbb53986906bc (patch) | |
| tree | e94ee657d160e397cc33a6e0cf8ce76b7d3d851d /net | |
| parent | ccff81e1d028bbbf8573d3364a87542386c707bf (diff) | |
| download | linux-a78cae2476812cecaa4a33d0086bbb53986906bc.tar.bz2 | |
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.c | 11 |
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); |