From: Ferdinand Blomqvist <ferdinand.blomqvist@xxxxxxxxx> [ Upstream commit ef4d6a8556b637ad27c8c2a2cff1dda3da38e9a9 ] Check if the syndrome provided by the caller is zero, and act accordingly. Signed-off-by: Ferdinand Blomqvist <ferdinand.blomqvist@xxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20190620141039.9874-6-ferdinand.blomqvist@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- lib/reed_solomon/decode_rs.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/lib/reed_solomon/decode_rs.c b/lib/reed_solomon/decode_rs.c index 3313bf944ff1..121beb2f0930 100644 --- a/lib/reed_solomon/decode_rs.c +++ b/lib/reed_solomon/decode_rs.c @@ -42,8 +42,18 @@ BUG_ON(pad < 0 || pad >= nn); /* Does the caller provide the syndrome ? */ - if (s != NULL) - goto decode; + if (s != NULL) { + for (i = 0; i < nroots; i++) { + /* The syndrome is in index form, + * so nn represents zero + */ + if (s[i] != nn) + goto decode; + } + + /* syndrome is zero, no errors to correct */ + return 0; + } /* form the syndromes; i.e., evaluate data(x) at roots of * g(x) */ -- 2.20.1
