Re: [PATCH net] net: dsa: b53: fix error propagation from b53_fdb_dump()

From: Florian Fainelli

Date: Wed Aug 12 2026 - 16:24:36 EST


On 8/12/26 13:11, Vladimir Oltean wrote:
The blamed commit replaced "return ret" statements in b53_fdb_dump()
with "break;" which jumps to the mutex_unlock() -> return 0 section.

This is notably problematic because it swallows errors from the
b53_fdb_copy() -> cb() path, and this will result in FDB dump truncation
when the netlink skb overflows - see commit 21b52fed928e ("net: dsa:
sja1105: fix broken backpressure in .port_fdb_dump").

Let's go back to "return ret". We don't need to preinitialize "ret" with
0, because the "do {} while" block guarantees we cannot reach the end of
the function without at least once calling b53_arl_search_wait(), which
will have initialized ret to some valid value.

Fixes: f7eb4a1c0864 ("net: dsa: b53: serialize access to the ARL table")
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>

Reviewed-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>
--
Florian