Greg Kurz wrote on Wed, Aug 01, 2018: > > @@ -263,13 +261,13 @@ p9_tag_alloc(struct p9_client *c, int8_t type, > > unsigned int max_size) > > if (!req) > > return NULL; > > > > - req->tc = p9_fcall_alloc(alloc_msize); > > - req->rc = p9_fcall_alloc(alloc_msize); > > - if (!req->tc || !req->rc) > > + if (p9_fcall_alloc(&req->tc, alloc_msize)) > > + goto free; > > + if (p9_fcall_alloc(&req->rc, alloc_msize)) > > goto free; > > Hmm... if the first allocation fails, we will kfree() req->rc.sdata. > > Are we sure we won't have a stale pointer or uninitialized data in > there ?
Yeah, Jun pointed that out and I have a v2 that only frees as needed with an extra goto (I sent an incremental diff in my reply to his comment here[1]) [1] https://lkml.kernel.org/r/20180731011256.GA30388@nautica > And even if we don't with the current code base, this is fragile and > could be easily broken. > > I think you should drop this hunk and rather rename p9_fcall_alloc() to > p9_fcall_alloc_sdata() instead, since this is what the function is > actually doing with this patch applied. Hmm. I agree the naming isn't accurate, but even if we rename it we'll need to pass a pointer to fcall as argument as it inits its capacity. p9_fcall_init(fc, msize) might be simpler? (I'm not sure I follow what you mean by 'drop this hunk', to be honest, did you want a single function call to init both maybe?) -- Dominique
