Messages in this thread | | | Date | Fri, 12 Aug 2022 15:41:46 +0200 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH] drivers: binderfs: fix memory leak in binderfs_fill_super |
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On Fri, Aug 12, 2022 at 09:21:24PM +0800, Dongliang Mu wrote: > From: Dongliang Mu <mudongliangabcd@gmail.com> > > In binderfs_fill_super, if s_root is not successfully initialized by > d_make_root, the previous allocated s_sb_info will not be freed since > generic_shutdown_super first checks if sb->s_root and then does > put_super operation. The put_super operation calls binderfs_put_super > to deallocate s_sb_info and put ipc_ns. This will lead to memory leak > in binderfs_fill_super. > > Fix this by invoking binderfs_put_super at error sites before s_root > is successfully initialized. > > Fixes: 095cf502b31e ("binderfs: port to new mount api") > Reported-by: syzkaller <syzkaller@googlegroups.com>
Where is the specific syzkaller link for this report? It would be good to reference it so it can be properly checked.
Also, how did you test this change?
> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com> > --- > drivers/android/binderfs.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c > index 588d753a7a19..20f5bc77495f 100644 > --- a/drivers/android/binderfs.c > +++ b/drivers/android/binderfs.c > @@ -710,8 +710,10 @@ static int binderfs_fill_super(struct super_block *sb, struct fs_context *fc) > info->mount_opts.stats_mode = ctx->stats_mode; > > inode = new_inode(sb); > - if (!inode) > + if (!inode) { > + binderfs_put_super(sb); > return -ENOMEM; > + } > > inode->i_ino = FIRST_INODE; > inode->i_fop = &simple_dir_operations; > @@ -721,8 +723,10 @@ static int binderfs_fill_super(struct super_block *sb, struct fs_context *fc) > set_nlink(inode, 2); > > sb->s_root = d_make_root(inode); > - if (!sb->s_root) > + if (!sb->s_root) { > + binderfs_put_super(sb); > return -ENOMEM; > + }
How did you test this change to verify that you are not now just leaking memory? It looks to me like you just changed one problem for another one :(
Please always be very very careful when making these types of changes, and verify and test that they are correct.
thanks,
greg k-h
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