| Message ID | 20230525205556.680DCC433EF@smtp.kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | + ocfs2-fix-use-after-free-when-unmounting-read-only-filesystem.patch added to mm-hotfixes-unstable branch | expand |
Hi Andrew, There is an updated version v2, which describe more clearly about the case: https://lore.kernel.org/ocfs2-devel/e9fc4b2f-1fcc-7c31-f346-59eccff50f9b@linux.alibaba.com/T/#u Thanks, Joseph On 5/26/23 4:55 AM, Andrew Morton wrote: > The patch titled > Subject: ocfs2: fix use-after-free when unmounting read-only filesystem > has been added to the -mm mm-hotfixes-unstable branch. Its filename is > ocfs2-fix-use-after-free-when-unmounting-read-only-filesystem.patch > > This patch will shortly appear at > https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ocfs2-fix-use-after-free-when-unmounting-read-only-filesystem.patch > > This patch will later appear in the mm-hotfixes-unstable branch at > git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm > > Before you just go and hit "reply", please: > a) Consider who else should be cc'ed > b) Prefer to cc a suitable mailing list as well > c) Ideally: find the original patch on the mailing list and do a > reply-to-all to that, adding suitable additional cc's > > *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** > > The -mm tree is included into linux-next via the mm-everything > branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm > and is updated there every 2-3 working days > > ------------------------------------------------------ > From: Luís Henriques <ocfs2-devel@oss.oracle.com> > Subject: ocfs2: fix use-after-free when unmounting read-only filesystem > Date: Mon, 22 May 2023 11:21:12 +0100 > > It's trivial to trigger a use-after-free bug in the ocfs2 quotas code > using fstest generic/452. After mounting a filesystem as read-only, > quotas are suspended and ocfs2_mem_dqinfo is freed through > ->ocfs2_local_free_info(). When unmounting the filesystem, an UAF access > to the oinfo will eventually cause a crash. > > Link: https://lkml.kernel.org/r/20230522102112.9031-1-lhenriques@suse.de > Signed-off-by: Luís Henriques <lhenriques@suse.de> > Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> > Tested-by: Joseph Qi <joseph.qi@linux.alibaba.com> > Cc: Mark Fasheh <mark@fasheh.com> > Cc: Joel Becker <jlbec@evilplan.org> > Cc: Junxiao Bi <junxiao.bi@oracle.com> > Cc: Changwei Ge <gechangwei@live.cn> > Cc: Gang He <ghe@suse.com> > Cc: Jun Piao <piaojun@huawei.com> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > --- > > fs/ocfs2/super.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > --- a/fs/ocfs2/super.c~ocfs2-fix-use-after-free-when-unmounting-read-only-filesystem > +++ a/fs/ocfs2/super.c > @@ -952,8 +952,10 @@ static void ocfs2_disable_quotas(struct > for (type = 0; type < OCFS2_MAXQUOTAS; type++) { > if (!sb_has_quota_loaded(sb, type)) > continue; > - oinfo = sb_dqinfo(sb, type)->dqi_priv; > - cancel_delayed_work_sync(&oinfo->dqi_sync_work); > + if (!sb_has_quota_suspended(sb, type)) { > + oinfo = sb_dqinfo(sb, type)->dqi_priv; > + cancel_delayed_work_sync(&oinfo->dqi_sync_work); > + } > inode = igrab(sb->s_dquot.files[type]); > /* Turn off quotas. This will remove all dquot structures from > * memory and so they will be automatically synced to global > _ > > Patches currently in -mm which might be from ocfs2-devel@oss.oracle.com are > > ocfs2-fix-use-after-free-when-unmounting-read-only-filesystem.patch
On Fri, 26 May 2023 09:36:25 +0800 Joseph Qi <joseph.qi@linux.alibaba.com> wrote: > Hi Andrew, > > There is an updated version v2, which describe more clearly about the > case: > https://lore.kernel.org/ocfs2-devel/e9fc4b2f-1fcc-7c31-f346-59eccff50f9b@linux.alibaba.com/T/#u Sigh. Thanks. As you can see from the above link, the email never hit ocfs2-devel and never hit my inbox. I'll piece it together from your reply. The ocfs2-devel list is really bad. Can we move to a vger list? Or get some maintenance work done on ocfs2-devel?
On 5/26/23 10:05 AM, Andrew Morton wrote: > On Fri, 26 May 2023 09:36:25 +0800 Joseph Qi <joseph.qi@linux.alibaba.com> wrote: > >> Hi Andrew, >> >> There is an updated version v2, which describe more clearly about the >> case: >> https://lore.kernel.org/ocfs2-devel/e9fc4b2f-1fcc-7c31-f346-59eccff50f9b@linux.alibaba.com/T/#u > > Sigh. Thanks. > > As you can see from the above link, the email never hit ocfs2-devel and > never hit my inbox. I'll piece it together from your reply. > Sorry for the inconvenience. I quote the updated description below: " It's trivial to trigger a use-after-free bug in the ocfs2 quotas code using fstest generic/452. After a read-only remount, quotas are suspended and ocfs2_mem_dqinfo is freed through ->ocfs2_local_free_info(). When unmounting the filesystem, an UAF access to the oinfo will eventually cause a crash. BUG: KASAN: slab-use-after-free in timer_delete+0x54/0xc0 Read of size 8 at addr ffff8880389a8208 by task umount/669 ... Call Trace: <TASK> ... timer_delete+0x54/0xc0 try_to_grab_pending+0x31/0x230 __cancel_work_timer+0x6c/0x270 ocfs2_disable_quotas.isra.0+0x3e/0xf0 [ocfs2] ocfs2_dismount_volume+0xdd/0x450 [ocfs2] generic_shutdown_super+0xaa/0x280 kill_block_super+0x46/0x70 deactivate_locked_super+0x4d/0xb0 cleanup_mnt+0x135/0x1f0 ... </TASK> Allocated by task 632: kasan_save_stack+0x1c/0x40 kasan_set_track+0x21/0x30 __kasan_kmalloc+0x8b/0x90 ocfs2_local_read_info+0xe3/0x9a0 [ocfs2] dquot_load_quota_sb+0x34b/0x680 dquot_load_quota_inode+0xfe/0x1a0 ocfs2_enable_quotas+0x190/0x2f0 [ocfs2] ocfs2_fill_super+0x14ef/0x2120 [ocfs2] mount_bdev+0x1be/0x200 legacy_get_tree+0x6c/0xb0 vfs_get_tree+0x3e/0x110 path_mount+0xa90/0xe10 __x64_sys_mount+0x16f/0x1a0 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc Freed by task 650: kasan_save_stack+0x1c/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x2a/0x50 __kasan_slab_free+0xf9/0x150 __kmem_cache_free+0x89/0x180 ocfs2_local_free_info+0x2ba/0x3f0 [ocfs2] dquot_disable+0x35f/0xa70 ocfs2_susp_quotas.isra.0+0x159/0x1a0 [ocfs2] ocfs2_remount+0x150/0x580 [ocfs2] reconfigure_super+0x1a5/0x3a0 path_mount+0xc8a/0xe10 __x64_sys_mount+0x16f/0x1a0 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc " > The ocfs2-devel list is really bad. Can we move to a vger list? Or > get some maintenance work done on ocfs2-devel? > I see. It seems something wrong with ocfs2-devel. But I'm not an administrator of it:( Thanks, Joseph
--- a/fs/ocfs2/super.c~ocfs2-fix-use-after-free-when-unmounting-read-only-filesystem +++ a/fs/ocfs2/super.c @@ -952,8 +952,10 @@ static void ocfs2_disable_quotas(struct for (type = 0; type < OCFS2_MAXQUOTAS; type++) { if (!sb_has_quota_loaded(sb, type)) continue; - oinfo = sb_dqinfo(sb, type)->dqi_priv; - cancel_delayed_work_sync(&oinfo->dqi_sync_work); + if (!sb_has_quota_suspended(sb, type)) { + oinfo = sb_dqinfo(sb, type)->dqi_priv; + cancel_delayed_work_sync(&oinfo->dqi_sync_work); + } inode = igrab(sb->s_dquot.files[type]); /* Turn off quotas. This will remove all dquot structures from * memory and so they will be automatically synced to global
The patch titled Subject: ocfs2: fix use-after-free when unmounting read-only filesystem has been added to the -mm mm-hotfixes-unstable branch. Its filename is ocfs2-fix-use-after-free-when-unmounting-read-only-filesystem.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ocfs2-fix-use-after-free-when-unmounting-read-only-filesystem.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Luís Henriques <ocfs2-devel@oss.oracle.com> Subject: ocfs2: fix use-after-free when unmounting read-only filesystem Date: Mon, 22 May 2023 11:21:12 +0100 It's trivial to trigger a use-after-free bug in the ocfs2 quotas code using fstest generic/452. After mounting a filesystem as read-only, quotas are suspended and ocfs2_mem_dqinfo is freed through ->ocfs2_local_free_info(). When unmounting the filesystem, an UAF access to the oinfo will eventually cause a crash. Link: https://lkml.kernel.org/r/20230522102112.9031-1-lhenriques@suse.de Signed-off-by: Luís Henriques <lhenriques@suse.de> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Tested-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- fs/ocfs2/super.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)