merged into cifs-2.6.git for-next On Mon, Oct 30, 2017 at 10:03 AM, Aurélien Aptel <aaptel@xxxxxxxx> wrote: > Elena Reshetova <elena.reshetova@xxxxxxxxx> writes: >> atomic_t variables are currently used to implement reference >> counters with the following properties: >> - counter is initialized to 1 using atomic_set() >> - a resource is freed upon counter reaching zero >> - once counter reaches zero, its further >> increments aren't allowed >> - counter schema uses basic atomic operations >> (set, inc, inc_not_zero, dec_and_test, etc.) >> >> Such atomic variables should be converted to a newly provided >> refcount_t type and API that prevents accidental counter overflows >> and underflows. This is important since overflows and underflows >> can lead to use-after-free situation and be exploitable. >> >> The variable tcon_link.tl_count is used as pure reference counter. >> Convert it to refcount_t and fix up the operations. > > <snip> > >> - cifs_get_tlink(tlink); >> + refcount_set(&tlink->tl_count, 1); > > Since cifs_get_tlink() basically only increments the reference count and > given that this is a new tlink I also think this replacement is ok. > > Looks good to me and passes 'make C=1'. > > Reviewed-by: Aurelien Aptel <aaptel@xxxxxxxx> > > -- > Aurélien Aptel / SUSE Labs Samba Team > GPG: 1839 CB5F 9F5B FB9B AA97 8C99 03C8 A49B 521B D5D3 > SUSE Linux GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany > GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) > -- > To unsubscribe from this list: send the line "unsubscribe linux-cifs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Thanks, Steve -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
