From: Amery Hung Date: Mon, 22 Sep 2025 23:33:49 +0000 (-0700) Subject: bpf: Clear pfmemalloc flag when freeing all fragments X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8f12d1137c2382c80aada8e05d7cc650cd4e403c;p=thirdparty%2Fkernel%2Fstable.git bpf: Clear pfmemalloc flag when freeing all fragments It is possible for bpf_xdp_adjust_tail() to free all fragments. The kfunc currently clears the XDP_FLAGS_HAS_FRAGS bit, but not XDP_FLAGS_FRAGS_PF_MEMALLOC. So far, this has not caused a issue when building sk_buff from xdp_buff since all readers of xdp_buff->flags use the flag only when there are fragments. Clear the XDP_FLAGS_FRAGS_PF_MEMALLOC bit as well to make the flags correct. Signed-off-by: Amery Hung Signed-off-by: Martin KaFai Lau Reviewed-by: Maciej Fijalkowski Link: https://patch.msgid.link/20250922233356.3356453-2-ameryhung@gmail.com --- diff --git a/include/net/xdp.h b/include/net/xdp.h index b40f1f96cb117..f288c348a6c13 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -115,6 +115,11 @@ static __always_inline void xdp_buff_set_frag_pfmemalloc(struct xdp_buff *xdp) xdp->flags |= XDP_FLAGS_FRAGS_PF_MEMALLOC; } +static __always_inline void xdp_buff_clear_frag_pfmemalloc(struct xdp_buff *xdp) +{ + xdp->flags &= ~XDP_FLAGS_FRAGS_PF_MEMALLOC; +} + static __always_inline void xdp_init_buff(struct xdp_buff *xdp, u32 frame_sz, struct xdp_rxq_info *rxq) { diff --git a/net/core/filter.c b/net/core/filter.c index 63f3baee2dafa..5837534f4352b 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4210,6 +4210,7 @@ static int bpf_xdp_frags_shrink_tail(struct xdp_buff *xdp, int offset) if (unlikely(!sinfo->nr_frags)) { xdp_buff_clear_frags_flag(xdp); + xdp_buff_clear_frag_pfmemalloc(xdp); xdp->data_end -= offset; }