Mercurial > illumos > illumos-gate
changeset 12645:0de9ed7d05ab
6942874 Loop in autofs/lofs mount causes stack overflow, leading to crash
| author | Jan Kryl <Jan.Kryl@Sun.COM> |
|---|---|
| date | Fri, 18 Jun 2010 13:58:16 +0200 |
| parents | 4f9a0cd40c5f |
| children | 6faf82030b5c |
| files | usr/src/uts/common/fs/lofs/lofs_vfsops.c |
| diffstat | 1 files changed, 15 insertions(+), 5 deletions(-) [+] |
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--- a/usr/src/uts/common/fs/lofs/lofs_vfsops.c Thu Jun 17 17:23:59 2010 -0700 +++ b/usr/src/uts/common/fs/lofs/lofs_vfsops.c Fri Jun 18 13:58:16 2010 +0200 @@ -277,12 +277,22 @@ } /* - * realrootvp may be an AUTOFS node, in which case we - * perform a VOP_ACCESS() to trigger the mount of the - * intended filesystem, so we loopback mount the intended - * filesystem instead of the AUTOFS filesystem. + * realrootvp may be an AUTOFS node, in which case we perform a + * VOP_ACCESS() to trigger the mount of the intended filesystem. + * This causes a loopback mount of the intended filesystem instead + * of the AUTOFS filesystem. + * + * If a lofs mount creates a mount loop (such that a lofs vfs is + * mounted on an autofs node and that lofs vfs points back to the + * autofs node which it is mounted on) then a VOP_ACCESS call will + * create a deadlock. Once this deadlock is released, VOP_ACCESS will + * return EINTR. In such a case we don't want the lofs vfs to be + * created as the loop could panic the system. */ - (void) VOP_ACCESS(realrootvp, 0, 0, cr, NULL); + if ((error = VOP_ACCESS(realrootvp, 0, 0, cr, NULL)) != 0) { + VN_RELE(realrootvp); + return (error); + } /* * We're interested in the top most filesystem.