| Message ID | 20190719124329.23207-1-nh26223.lmm@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fs: fs_parser: avoid NULL param->string to kstrtouint | expand |
On Fri, Jul 19, 2019 at 2:44 PM Yin Fengwei <nh26223.lmm@gmail.com> wrote: > > syzbot reported general protection fault in kstrtouint: > https://lkml.org/lkml/2019/7/18/328 > > From the log, if the mount option is something like: > fd,XXXXXXXXXXXXXXXXXXXX > > The default parameter (which has NULL param->string) will be > passed to vfs_parse_fs_param. Finally, this NULL param->string > is passed to kstrtouint and trigger NULL pointer access. > > Reported-by: syzbot+398343b7c1b1b989228d@syzkaller.appspotmail.com > Fixes: 71cbb7570a9a ("vfs: Move the subtype parameter into fuse") > > Signed-off-by: Yin Fengwei <nh26223.lmm@gmail.com> > --- > fs/fs_parser.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/fs/fs_parser.c b/fs/fs_parser.c > index d13fe7d797c2..578e6880ac67 100644 > --- a/fs/fs_parser.c > +++ b/fs/fs_parser.c > @@ -210,6 +210,10 @@ int fs_parse(struct fs_context *fc, > case fs_param_is_fd: { > switch (param->type) { > case fs_value_is_string: > + if (result->has_value) { !result->has_value ? > + goto bad_value; > + } > + > ret = kstrtouint(param->string, 0, &result->uint_32); > break; > case fs_value_is_file: > -- > 2.17.1 > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/20190719124329.23207-1-nh26223.lmm%40gmail.com.
On Fri, Jul 19, 2019 at 08:43:29PM +0800, Yin Fengwei wrote: > syzbot reported general protection fault in kstrtouint: > https://lkml.org/lkml/2019/7/18/328 > > >From the log, if the mount option is something like: > fd,XXXXXXXXXXXXXXXXXXXX > > The default parameter (which has NULL param->string) will be > passed to vfs_parse_fs_param. Finally, this NULL param->string > is passed to kstrtouint and trigger NULL pointer access. > > Reported-by: syzbot+398343b7c1b1b989228d@syzkaller.appspotmail.com > Fixes: 71cbb7570a9a ("vfs: Move the subtype parameter into fuse") > > Signed-off-by: Yin Fengwei <nh26223.lmm@gmail.com> > --- > fs/fs_parser.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/fs/fs_parser.c b/fs/fs_parser.c > index d13fe7d797c2..578e6880ac67 100644 > --- a/fs/fs_parser.c > +++ b/fs/fs_parser.c > @@ -210,6 +210,10 @@ int fs_parse(struct fs_context *fc, > case fs_param_is_fd: { > switch (param->type) { > case fs_value_is_string: > + if (result->has_value) { > + goto bad_value; > + } Always run checkpatch.pl so grumpy maintainers do not tell you to go run checkpatch.pl :)
On Fri, Jul 19, 2019 at 03:37:37PM +0200, Dmitry Vyukov wrote: > On Fri, Jul 19, 2019 at 2:44 PM Yin Fengwei <nh26223.lmm@gmail.com> wrote: > > > > syzbot reported general protection fault in kstrtouint: > > https://lkml.org/lkml/2019/7/18/328 > > > > From the log, if the mount option is something like: > > fd,XXXXXXXXXXXXXXXXXXXX > > > > The default parameter (which has NULL param->string) will be > > passed to vfs_parse_fs_param. Finally, this NULL param->string > > is passed to kstrtouint and trigger NULL pointer access. > > > > Reported-by: syzbot+398343b7c1b1b989228d@syzkaller.appspotmail.com > > Fixes: 71cbb7570a9a ("vfs: Move the subtype parameter into fuse") > > > > Signed-off-by: Yin Fengwei <nh26223.lmm@gmail.com> > > --- > > fs/fs_parser.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/fs/fs_parser.c b/fs/fs_parser.c > > index d13fe7d797c2..578e6880ac67 100644 > > --- a/fs/fs_parser.c > > +++ b/fs/fs_parser.c > > @@ -210,6 +210,10 @@ int fs_parse(struct fs_context *fc, > > case fs_param_is_fd: { > > switch (param->type) { > > case fs_value_is_string: > > + if (result->has_value) { > > !result->has_value ? Yes. Should have ! in condition for NULL param->string. Will fix in v2. Regards Yin, Fengwei > > > + goto bad_value; > > + } > > + > > ret = kstrtouint(param->string, 0, &result->uint_32); > > break; > > case fs_value_is_file: > > -- > > 2.17.1 > > > > -- > > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. > > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/20190719124329.23207-1-nh26223.lmm%40gmail.com.
On Fri, Jul 19, 2019 at 07:38:11PM +0200, Greg KH wrote: > On Fri, Jul 19, 2019 at 08:43:29PM +0800, Yin Fengwei wrote: > > syzbot reported general protection fault in kstrtouint: > > https://lkml.org/lkml/2019/7/18/328 > > > > >From the log, if the mount option is something like: > > fd,XXXXXXXXXXXXXXXXXXXX > > > > The default parameter (which has NULL param->string) will be > > passed to vfs_parse_fs_param. Finally, this NULL param->string > > is passed to kstrtouint and trigger NULL pointer access. > > > > Reported-by: syzbot+398343b7c1b1b989228d@syzkaller.appspotmail.com > > Fixes: 71cbb7570a9a ("vfs: Move the subtype parameter into fuse") > > > > Signed-off-by: Yin Fengwei <nh26223.lmm@gmail.com> > > --- > > fs/fs_parser.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/fs/fs_parser.c b/fs/fs_parser.c > > index d13fe7d797c2..578e6880ac67 100644 > > --- a/fs/fs_parser.c > > +++ b/fs/fs_parser.c > > @@ -210,6 +210,10 @@ int fs_parse(struct fs_context *fc, > > case fs_param_is_fd: { > > switch (param->type) { > > case fs_value_is_string: > > + if (result->has_value) { > > + goto bad_value; > > + } > > Always run checkpatch.pl so grumpy maintainers do not tell you to go run > checkpatch.pl :) Thanks a lot for kindly reminder. Will be careful for future patch. :) Regards Yin, Fengwei
diff --git a/fs/fs_parser.c b/fs/fs_parser.c index d13fe7d797c2..578e6880ac67 100644 --- a/fs/fs_parser.c +++ b/fs/fs_parser.c @@ -210,6 +210,10 @@ int fs_parse(struct fs_context *fc, case fs_param_is_fd: { switch (param->type) { case fs_value_is_string: + if (result->has_value) { + goto bad_value; + } + ret = kstrtouint(param->string, 0, &result->uint_32); break; case fs_value_is_file:
syzbot reported general protection fault in kstrtouint: https://lkml.org/lkml/2019/7/18/328 From the log, if the mount option is something like: fd,XXXXXXXXXXXXXXXXXXXX The default parameter (which has NULL param->string) will be passed to vfs_parse_fs_param. Finally, this NULL param->string is passed to kstrtouint and trigger NULL pointer access. Reported-by: syzbot+398343b7c1b1b989228d@syzkaller.appspotmail.com Fixes: 71cbb7570a9a ("vfs: Move the subtype parameter into fuse") Signed-off-by: Yin Fengwei <nh26223.lmm@gmail.com> --- fs/fs_parser.c | 4 ++++ 1 file changed, 4 insertions(+)