Re: [PATCH net v1 1/3] net: core: propagate unreadable flag in skb_zerocopy

From
Pavel Begunkov <asml.silence@gmail.com>
Date
2026-08-02 12:33:13
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Reply to
Mina Almasry, 2026-08-01
On 8/1/26 13:52, Mina Almasry wrote:
When skb_zerocopy() copies devmem payload fragments, it fails to update
the target skb's unreadable flag. This causes the target to appear as
readable memory.

Propagate the unreadable flag if any devmem fragments were copied from
the source.
From a quick look, it doesn't seem like the function would work reliably
with netmems even with this patch, but that's a different kind of issue
we can return to later. Curious, did you hit this in prod?

Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Fixes: 65249feb6b3d ("net: add support for skbs with unreadable frags")
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Stanislav Fomichev <sdf@fomichev.me>
Cc: Bobby Eshleman <redacted>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: Mina Almasry <redacted>
---
  net/core/skbuff.c | 3 +++
  1 file changed, 3 insertions(+)
-- 
Pavel Begunkov
Thread (8 messages) 8 messages, 2 authors, last reply 2026-08-03
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