Re: [PATCH v15 2/9] namei: LOOKUP_NO_MAGICLINKS: block magic-link resolution
From: Al Viro <viro@zeniv.linux.org.uk>
Date: 2019-11-13 01:27:08
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On Tue, Nov 05, 2019 at 08:05:46PM +1100, Aleksa Sarai wrote:
quoted hunk ↗ jump to hunk
@@ -1078,6 +1079,10 @@ const char *get_link(struct nameidata *nd) } else { res = get(dentry, inode, &last->done); } + if (nd->flags & LOOKUP_MAGICLINK_JUMPED) { + if (unlikely(nd->flags & LOOKUP_NO_MAGICLINKS)) + return ERR_PTR(-ELOOP); + }
Minor nit - the first check probably wants unlikely() more than the second one; it's probably noise anyway, but most of the symlinks traversed are not going to be procfs ones, so you get test + branch taken most of the time. OTOH, that just might compile into fetch nd->flags and with LOOKUP_MAGICLINK_JUMPED | LOOKUP_NO_MAGICLINKS compare with the same constant unlikely branch when equal Anyway, that's no more than a minor nit and can be dealt with later (if at all) _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel