| Message ID | 768760.1716567475@warthog.procyon.org.uk (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | afs: Don't cross .backup mountpoint from backup volume | expand |
On 5/24/2024 12:17 PM, David Howells wrote: > Hi Christian, > > Can you pick this up, please? > > Thanks, > David > --- > From: Marc Dionne<marc.dionne@auristor.com> > > afs: Don't cross .backup mountpoint from backup volume > > Don't cross a mountpoint that explicitly specifies a backup volume > (target is <vol>.backup) when starting from a backup volume. > > It it not uncommon to mount a volume's backup directly in the volume > itself. This can cause tools that are not paying attention to get > into a loop mounting the volume onto itself as they attempt to > traverse the tree, leading to a variety of problems. > > This doesn't prevent the general case of loops in a sequence of > mountpoints, but addresses a common special case in the same way > as other afs clients. > > Reported-by: Jan Henrik Sylvester<jan.henrik.sylvester@uni-hamburg.de> > Link:http://lists.infradead.org/pipermail/linux-afs/2024-May/008454.html > Reported-by: Markus Suvanto<markus.suvanto@gmail.com> > Link:http://lists.infradead.org/pipermail/linux-afs/2024-February/008074.html > Signed-off-by: Marc Dionne<marc.dionne@auristor.com> > Signed-off-by: David Howells<dhowells@redhat.com> > Reviewed-by: Jeffrey Altman<jaltman@auristor.com> > cc:linux-afs@lists.infradead.org > --- > fs/afs/mntpt.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c > index 97f50e9fd9eb..297487ee8323 100644 > --- a/fs/afs/mntpt.c > +++ b/fs/afs/mntpt.c > @@ -140,6 +140,11 @@ static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt) > put_page(page); > if (ret < 0) > return ret; > + > + /* Don't cross a backup volume mountpoint from a backup volume */ > + if (src_as->volume && src_as->volume->type == AFSVL_BACKVOL && > + ctx->type == AFSVL_BACKVOL) > + return -ENODEV; > } > > return 0; Please add cc: stable@vger.kernel.org when it is applied to vfs-fixes. Thank you. Jeffrey Altman
On 5/24/2024 12:17 PM, David Howells wrote: > Hi Christian, > > Can you pick this up, please? > > Thanks, > David > --- > From: Marc Dionne<marc.dionne@auristor.com> > > afs: Don't cross .backup mountpoint from backup volume > > Don't cross a mountpoint that explicitly specifies a backup volume > (target is <vol>.backup) when starting from a backup volume. > > It it not uncommon to mount a volume's backup directly in the volume > itself. This can cause tools that are not paying attention to get > into a loop mounting the volume onto itself as they attempt to > traverse the tree, leading to a variety of problems. > > This doesn't prevent the general case of loops in a sequence of > mountpoints, but addresses a common special case in the same way > as other afs clients. > > Reported-by: Jan Henrik Sylvester<jan.henrik.sylvester@uni-hamburg.de> > Link:http://lists.infradead.org/pipermail/linux-afs/2024-May/008454.html > Reported-by: Markus Suvanto<markus.suvanto@gmail.com> > Link:http://lists.infradead.org/pipermail/linux-afs/2024-February/008074.html > Signed-off-by: Marc Dionne<marc.dionne@auristor.com> > Signed-off-by: David Howells<dhowells@redhat.com> > Reviewed-by: Jeffrey Altman<jaltman@auristor.com> > cc:linux-afs@lists.infradead.org > --- > fs/afs/mntpt.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c > index 97f50e9fd9eb..297487ee8323 100644 > --- a/fs/afs/mntpt.c > +++ b/fs/afs/mntpt.c > @@ -140,6 +140,11 @@ static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt) > put_page(page); > if (ret < 0) > return ret; > + > + /* Don't cross a backup volume mountpoint from a backup volume */ > + if (src_as->volume && src_as->volume->type == AFSVL_BACKVOL && > + ctx->type == AFSVL_BACKVOL) > + return -ENODEV; > } > > return 0; Please add cc: stable@vger.kernel.org when it is applied to vfs-fixes. Thank you. Jeffrey Altman
diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c index 97f50e9fd9eb..297487ee8323 100644 --- a/fs/afs/mntpt.c +++ b/fs/afs/mntpt.c @@ -140,6 +140,11 @@ static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt) put_page(page); if (ret < 0) return ret; + + /* Don't cross a backup volume mountpoint from a backup volume */ + if (src_as->volume && src_as->volume->type == AFSVL_BACKVOL && + ctx->type == AFSVL_BACKVOL) + return -ENODEV; } return 0;