On Wed 2020-10-14 19:50:54, Petr Mladek wrote: > data_realloc() returns wrong data pointer when the block is wrapped and > the size is not increased. It might happen when pr_cont() wants to > add only few characters and there is already a space for them because > of alignment. > > It might cause writing outsite the buffer. It has been detected by LTP > tests with KASAN enabled: > > Link: https://lore.kernel.org/r/CA+G9fYt46oC7-BKryNDaaXPJ9GztvS2cs_7GjYRjanRi4+ryCQ@xxxxxxxxxxxxxx > Fixes: 4cfc7258f876a7feba673ac ("printk: ringbuffer: add finalization/extension support") > Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> > Signed-off-by: Petr Mladek <pmladek@xxxxxxxx> The patch is committed into printk/linux.git, branch for-5.10-fixup. I am going to send a pull request with it tomorrow unless something happens in the meantime. Best Regards, Petr
