| Message ID | 1476371737-2116-1-git-send-email-geert@linux-m68k.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Oct 13, 2016 at 11:15 PM, Geert Uytterhoeven <geert@linux-m68k.org> wrote: > fs/ceph/super.c: In function ‘ceph_real_mount’: > fs/ceph/super.c:818: warning: ‘root’ may be used uninitialized in this function > > If s_root is already valid, dentry pointer root is never initialized, > and returned by ceph_real_mount(). This will cause a crash later when > the caller dereferences the pointer. > > Fix this by initializing root early. > > Fixes: ce2728aaa82bbeba ("ceph: avoid accessing / when mounting a subpath") > Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> > --- > Compile-tested only. > --- > fs/ceph/super.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/ceph/super.c b/fs/ceph/super.c > index a29ffce981879d5f..794c5fd0e0cf5e45 100644 > --- a/fs/ceph/super.c > +++ b/fs/ceph/super.c > @@ -821,7 +821,8 @@ static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc) > dout("mount start %p\n", fsc); > mutex_lock(&fsc->client->mount_mutex); > > - if (!fsc->sb->s_root) { > + root = fsc->sb->s_root; > + if (!root) { > const char *path; > err = __ceph_open_session(fsc->client, started); > if (err < 0) For sb->s_root is not NULL case, we also need to increase sb->s_root's reference count. I applied this patch and fixed it. Regards Yan, Zheng > -- > 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Zheng, On Fri, Oct 14, 2016 at 4:47 AM, Yan, Zheng <ukernel@gmail.com> wrote: > On Thu, Oct 13, 2016 at 11:15 PM, Geert Uytterhoeven > <geert@linux-m68k.org> wrote: >> fs/ceph/super.c: In function ‘ceph_real_mount’: >> fs/ceph/super.c:818: warning: ‘root’ may be used uninitialized in this function >> >> If s_root is already valid, dentry pointer root is never initialized, >> and returned by ceph_real_mount(). This will cause a crash later when >> the caller dereferences the pointer. >> >> Fix this by initializing root early. >> >> Fixes: ce2728aaa82bbeba ("ceph: avoid accessing / when mounting a subpath") >> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> >> --- >> Compile-tested only. >> --- >> fs/ceph/super.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/fs/ceph/super.c b/fs/ceph/super.c >> index a29ffce981879d5f..794c5fd0e0cf5e45 100644 >> --- a/fs/ceph/super.c >> +++ b/fs/ceph/super.c >> @@ -821,7 +821,8 @@ static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc) >> dout("mount start %p\n", fsc); >> mutex_lock(&fsc->client->mount_mutex); >> >> - if (!fsc->sb->s_root) { >> + root = fsc->sb->s_root; >> + if (!root) { >> const char *path; >> err = __ceph_open_session(fsc->client, started); >> if (err < 0) > > For sb->s_root is not NULL case, we also need to increase sb->s_root's > reference count. OK > I applied this patch and fixed it. Thanks for handling! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/ceph/super.c b/fs/ceph/super.c index a29ffce981879d5f..794c5fd0e0cf5e45 100644 --- a/fs/ceph/super.c +++ b/fs/ceph/super.c @@ -821,7 +821,8 @@ static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc) dout("mount start %p\n", fsc); mutex_lock(&fsc->client->mount_mutex); - if (!fsc->sb->s_root) { + root = fsc->sb->s_root; + if (!root) { const char *path; err = __ceph_open_session(fsc->client, started); if (err < 0)
fs/ceph/super.c: In function ‘ceph_real_mount’: fs/ceph/super.c:818: warning: ‘root’ may be used uninitialized in this function If s_root is already valid, dentry pointer root is never initialized, and returned by ceph_real_mount(). This will cause a crash later when the caller dereferences the pointer. Fix this by initializing root early. Fixes: ce2728aaa82bbeba ("ceph: avoid accessing / when mounting a subpath") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> --- Compile-tested only. --- fs/ceph/super.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)