The log of UAF problem is listed below.
BUG: KASAN: use-after-free in jffs2_rmdir+0xa4/0x1cc [jffs2] at addr c1f165fc
Read of size 4 by task rm/8283
=============================================================================
BUG kmalloc-32 (Tainted: P B O ): kasan: bad access detected
-----------------------------------------------------------------------------
INFO: Allocated in 0xbbbbbbbb age=3054364 cpu=0 pid=0
0xb0bba6ef
jffs2_write_dirent+0x11c/0x9c8 [jffs2]
__slab_alloc.isra.21.constprop.25+0x2c/0x44
__kmalloc+0x1dc/0x370
jffs2_write_dirent+0x11c/0x9c8 [jffs2]
jffs2_do_unlink+0x328/0x5fc [jffs2]
jffs2_rmdir+0x110/0x1cc [jffs2]
vfs_rmdir+0x180/0x268
do_rmdir+0x2cc/0x300
ret_from_syscall+0x0/0x3c
INFO: Freed in 0x205b age=3054364 cpu=0 pid=0
0x2e9173
jffs2_add_fd_to_list+0x138/0x1dc [jffs2]
jffs2_add_fd_to_list+0x138/0x1dc [jffs2]
jffs2_garbage_collect_dirent.isra.3+0x21c/0x288 [jffs2]
jffs2_garbage_collect_live+0x16bc/0x1800 [jffs2]
jffs2_garbage_collect_pass+0x678/0x11d4 [jffs2]
jffs2_garbage_collect_thread+0x1e8/0x3b0 [jffs2]
kthread+0x1a8/0x1b0
ret_from_kernel_thread+0x5c/0x64
Call Trace:
[c17ddd20] [c02452d4] kasan_report.part.0+0x298/0x72c (unreliable)
[c17ddda0] [d2509680] jffs2_rmdir+0xa4/0x1cc [jffs2]
[c17dddd0] [c026da04] vfs_rmdir+0x180/0x268
[c17dde00] [c026f4e4] do_rmdir+0x2cc/0x300
[c17ddf40] [c001a658] ret_from_syscall+0x0/0x3c
The root cause is that we don't get "jffs2_inode_info.sem" before
we scan list "jffs2_inode_info.dents" in function jffs2_rmdir.
This patch add codes to get "jffs2_inode_info.sem" before we scan
"jffs2_inode_info.dents" to slove the UAF problem.
Signed-off-by: Zhe Li <[email protected]>
---
fs/jffs2/dir.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c
index f20cff1..7764937 100644
--- a/fs/jffs2/dir.c
+++ b/fs/jffs2/dir.c
@@ -590,10 +590,14 @@ static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
int ret;
uint32_t now = JFFS2_NOW();
+ mutex_lock(&f->sem);
for (fd = f->dents ; fd; fd = fd->next) {
- if (fd->ino)
+ if (fd->ino) {
+ mutex_unlock(&f->sem);
return -ENOTEMPTY;
+ }
}
+ mutex_unlock(&f->sem);
ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
dentry->d_name.len, f, now);
--
2.7.4
Reviewed-by: Hou Tao <[email protected]>
On 2020/6/19 17:06, Zhe Li wrote:
> The log of UAF problem is listed below.
> BUG: KASAN: use-after-free in jffs2_rmdir+0xa4/0x1cc [jffs2] at addr c1f165fc
> Read of size 4 by task rm/8283
> =============================================================================
> BUG kmalloc-32 (Tainted: P B O ): kasan: bad access detected
> -----------------------------------------------------------------------------
>
> INFO: Allocated in 0xbbbbbbbb age=3054364 cpu=0 pid=0
> 0xb0bba6ef
> jffs2_write_dirent+0x11c/0x9c8 [jffs2]
> __slab_alloc.isra.21.constprop.25+0x2c/0x44
> __kmalloc+0x1dc/0x370
> jffs2_write_dirent+0x11c/0x9c8 [jffs2]
> jffs2_do_unlink+0x328/0x5fc [jffs2]
> jffs2_rmdir+0x110/0x1cc [jffs2]
> vfs_rmdir+0x180/0x268
> do_rmdir+0x2cc/0x300
> ret_from_syscall+0x0/0x3c
> INFO: Freed in 0x205b age=3054364 cpu=0 pid=0
> 0x2e9173
> jffs2_add_fd_to_list+0x138/0x1dc [jffs2]
> jffs2_add_fd_to_list+0x138/0x1dc [jffs2]
> jffs2_garbage_collect_dirent.isra.3+0x21c/0x288 [jffs2]
> jffs2_garbage_collect_live+0x16bc/0x1800 [jffs2]
> jffs2_garbage_collect_pass+0x678/0x11d4 [jffs2]
> jffs2_garbage_collect_thread+0x1e8/0x3b0 [jffs2]
> kthread+0x1a8/0x1b0
> ret_from_kernel_thread+0x5c/0x64
> Call Trace:
> [c17ddd20] [c02452d4] kasan_report.part.0+0x298/0x72c (unreliable)
> [c17ddda0] [d2509680] jffs2_rmdir+0xa4/0x1cc [jffs2]
> [c17dddd0] [c026da04] vfs_rmdir+0x180/0x268
> [c17dde00] [c026f4e4] do_rmdir+0x2cc/0x300
> [c17ddf40] [c001a658] ret_from_syscall+0x0/0x3c
>
> The root cause is that we don't get "jffs2_inode_info.sem" before
> we scan list "jffs2_inode_info.dents" in function jffs2_rmdir.
> This patch add codes to get "jffs2_inode_info.sem" before we scan
> "jffs2_inode_info.dents" to slove the UAF problem.
>
> Signed-off-by: Zhe Li <[email protected]>
> ---
> fs/jffs2/dir.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c
> index f20cff1..7764937 100644
> --- a/fs/jffs2/dir.c
> +++ b/fs/jffs2/dir.c
> @@ -590,10 +590,14 @@ static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
> int ret;
> uint32_t now = JFFS2_NOW();
>
> + mutex_lock(&f->sem);
> for (fd = f->dents ; fd; fd = fd->next) {
> - if (fd->ino)
> + if (fd->ino) {
> + mutex_unlock(&f->sem);
> return -ENOTEMPTY;
> + }
> }
> + mutex_unlock(&f->sem);
>
> ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
> dentry->d_name.len, f, now);
>
Nice find, I just came across a deadlock wrt GC and rmdir,
hopefully this is he fix.
This needs to go to stable too, sooner rather than later.
Jocke
On Fri, 2020-06-19 at 17:06 +0800, Zhe Li wrote:
>
> The log of UAF problem is listed below.
> BUG: KASAN: use-after-free in jffs2_rmdir+0xa4/0x1cc [jffs2] at addr c1f165fc
> Read of size 4 by task rm/8283
> =============================================================================
> BUG kmalloc-32 (Tainted: P B O ): kasan: bad access detected
> -----------------------------------------------------------------------------
>
> INFO: Allocated in 0xbbbbbbbb age=3054364 cpu=0 pid=0
> 0xb0bba6ef
> jffs2_write_dirent+0x11c/0x9c8 [jffs2]
> __slab_alloc.isra.21.constprop.25+0x2c/0x44
> __kmalloc+0x1dc/0x370
> jffs2_write_dirent+0x11c/0x9c8 [jffs2]
> jffs2_do_unlink+0x328/0x5fc [jffs2]
> jffs2_rmdir+0x110/0x1cc [jffs2]
> vfs_rmdir+0x180/0x268
> do_rmdir+0x2cc/0x300
> ret_from_syscall+0x0/0x3c
> INFO: Freed in 0x205b age=3054364 cpu=0 pid=0
> 0x2e9173
> jffs2_add_fd_to_list+0x138/0x1dc [jffs2]
> jffs2_add_fd_to_list+0x138/0x1dc [jffs2]
> jffs2_garbage_collect_dirent.isra.3+0x21c/0x288 [jffs2]
> jffs2_garbage_collect_live+0x16bc/0x1800 [jffs2]
> jffs2_garbage_collect_pass+0x678/0x11d4 [jffs2]
> jffs2_garbage_collect_thread+0x1e8/0x3b0 [jffs2]
> kthread+0x1a8/0x1b0
> ret_from_kernel_thread+0x5c/0x64
> Call Trace:
> [c17ddd20] [c02452d4] kasan_report.part.0+0x298/0x72c (unreliable)
> [c17ddda0] [d2509680] jffs2_rmdir+0xa4/0x1cc [jffs2]
> [c17dddd0] [c026da04] vfs_rmdir+0x180/0x268
> [c17dde00] [c026f4e4] do_rmdir+0x2cc/0x300
> [c17ddf40] [c001a658] ret_from_syscall+0x0/0x3c
>
> The root cause is that we don't get "jffs2_inode_info.sem" before
> we scan list "jffs2_inode_info.dents" in function jffs2_rmdir.
> This patch add codes to get "jffs2_inode_info.sem" before we scan
> "jffs2_inode_info.dents" to slove the UAF problem.
>
> Signed-off-by: Zhe Li <[email protected]>
> ---
> fs/jffs2/dir.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c
> index f20cff1..7764937 100644
> --- a/fs/jffs2/dir.c
> +++ b/fs/jffs2/dir.c
> @@ -590,10 +590,14 @@ static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
> int ret;
> uint32_t now = JFFS2_NOW();
>
> + mutex_lock(&f->sem);
> for (fd = f->dents ; fd; fd = fd->next) {
> - if (fd->ino)
> + if (fd->ino) {
> + mutex_unlock(&f->sem);
> return -ENOTEMPTY;
> + }
> }
> + mutex_unlock(&f->sem);
>
> ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
> dentry->d_name.len, f, now);
> --
> 2.7.4
>
>
>
> ______________________________________________________
> Linux MTD discussion mailing list
> https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.infradead.org%2Fmailman%2Flistinfo%2Flinux-mtd%2F&data=02%7C01%7Cjoakim.tjernlund%40infinera.com%7C339a1184745b4c76bdf908d8143043b2%7C285643de5f5b4b03a1530ae2dc8aaf77%7C1%7C1%7C637281544815697582&sdata=jKo97fc3j6jVcjVpS2exm0sDL%2BWr6DqkTe6jqe8G9t8%3D&reserved=0
Maintainer ping ?
Jocke
On Wed, 2020-06-24 at 18:59 +0000, Joakim Tjernlund wrote:
>
> Nice find, I just came across a deadlock wrt GC and rmdir,
> hopefully this is he fix.
>
> This needs to go to stable too, sooner rather than later.
>
> Jocke
>
> On Fri, 2020-06-19 at 17:06 +0800, Zhe Li wrote:
> >
> > The log of UAF problem is listed below.
> > BUG: KASAN: use-after-free in jffs2_rmdir+0xa4/0x1cc [jffs2] at addr c1f165fc
> > Read of size 4 by task rm/8283
> > =============================================================================
> > BUG kmalloc-32 (Tainted: P B O ): kasan: bad access detected
> > -----------------------------------------------------------------------------
> >
> > INFO: Allocated in 0xbbbbbbbb age=3054364 cpu=0 pid=0
> > 0xb0bba6ef
> > jffs2_write_dirent+0x11c/0x9c8 [jffs2]
> > __slab_alloc.isra.21.constprop.25+0x2c/0x44
> > __kmalloc+0x1dc/0x370
> > jffs2_write_dirent+0x11c/0x9c8 [jffs2]
> > jffs2_do_unlink+0x328/0x5fc [jffs2]
> > jffs2_rmdir+0x110/0x1cc [jffs2]
> > vfs_rmdir+0x180/0x268
> > do_rmdir+0x2cc/0x300
> > ret_from_syscall+0x0/0x3c
> > INFO: Freed in 0x205b age=3054364 cpu=0 pid=0
> > 0x2e9173
> > jffs2_add_fd_to_list+0x138/0x1dc [jffs2]
> > jffs2_add_fd_to_list+0x138/0x1dc [jffs2]
> > jffs2_garbage_collect_dirent.isra.3+0x21c/0x288 [jffs2]
> > jffs2_garbage_collect_live+0x16bc/0x1800 [jffs2]
> > jffs2_garbage_collect_pass+0x678/0x11d4 [jffs2]
> > jffs2_garbage_collect_thread+0x1e8/0x3b0 [jffs2]
> > kthread+0x1a8/0x1b0
> > ret_from_kernel_thread+0x5c/0x64
> > Call Trace:
> > [c17ddd20] [c02452d4] kasan_report.part.0+0x298/0x72c (unreliable)
> > [c17ddda0] [d2509680] jffs2_rmdir+0xa4/0x1cc [jffs2]
> > [c17dddd0] [c026da04] vfs_rmdir+0x180/0x268
> > [c17dde00] [c026f4e4] do_rmdir+0x2cc/0x300
> > [c17ddf40] [c001a658] ret_from_syscall+0x0/0x3c
> >
> > The root cause is that we don't get "jffs2_inode_info.sem" before
> > we scan list "jffs2_inode_info.dents" in function jffs2_rmdir.
> > This patch add codes to get "jffs2_inode_info.sem" before we scan
> > "jffs2_inode_info.dents" to slove the UAF problem.
> >
> > Signed-off-by: Zhe Li <[email protected]>
> > ---
> > fs/jffs2/dir.c | 6 +++++-
> > 1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c
> > index f20cff1..7764937 100644
> > --- a/fs/jffs2/dir.c
> > +++ b/fs/jffs2/dir.c
> > @@ -590,10 +590,14 @@ static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
> > int ret;
> > uint32_t now = JFFS2_NOW();
> >
> > + mutex_lock(&f->sem);
> > for (fd = f->dents ; fd; fd = fd->next) {
> > - if (fd->ino)
> > + if (fd->ino) {
> > + mutex_unlock(&f->sem);
> > return -ENOTEMPTY;
> > + }
> > }
> > + mutex_unlock(&f->sem);
> >
> > ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
> > dentry->d_name.len, f, now);
> > --
> > 2.7.4
> >
> >
> >
On Tue, Jul 7, 2020 at 4:08 PM Joakim Tjernlund
<[email protected]> wrote:
>
> Maintainer ping ?
Whoops. Applied for fixes.
--
Thanks,
//richard
On Tue, 2020-07-07 at 18:30 +0200, Richard Weinberger wrote:
> CAUTION: This email originated from outside of the organization. Do
> not click links or open attachments unless you recognize the sender
> and know the content is safe.
>
>
> On Tue, Jul 7, 2020 at 4:08 PM Joakim Tjernlund
> <[email protected]> wrote:
> >
> > Maintainer ping ?
>
> Whoops. Applied for fixes.
Did you queue for stable too?
This bug has been there since day one for jffs2
On Mon, Jul 13, 2020 at 11:51 PM Joakim Tjernlund
<[email protected]> wrote:
> Did you queue for stable too?
> This bug has been there since day one for jffs2
It will. I just had no chance to re-create my setup after the
infradead.org meltdown. :-)
--
Thanks,
//richard