Re: [PATCH] f2fs: fix use-after-free issue with sbi->stat_info
On Tue, Dec 25, 2018 at 11:06:45AM +0800, Chao Yu wrote: > On 2018/12/24 21:06, Sahitya Tummala wrote: > > iput() on sbi->node_inode can update sbi->stat_info > > in the below context, if the f2fs_write_checkpoint() > > has failed with error. > > > > f2fs_balance_fs_bg+0x1ac/0x1ec > > f2fs_write_node_pages+0x4c/0x260 > > do_writepages+0x80/0xbc > > __writeback_single_inode+0xdc/0x4ac > > writeback_single_inode+0x9c/0x144 > > write_inode_now+0xc4/0xec > > iput+0x194/0x22c > > f2fs_put_super+0x11c/0x1e8 > > generic_shutdown_super+0x70/0xf4 > > kill_block_super+0x2c/0x5c > > kill_f2fs_super+0x44/0x50 > > deactivate_locked_super+0x60/0x8c > > deactivate_super+0x68/0x74 > > cleanup_mnt+0x40/0x78 > > > > Fix this by moving f2fs_destroy_stats() further below iput(). > > > > Signed-off-by: Sahitya Tummala > > --- > > fs/f2fs/super.c | 9 ++--- > > 1 file changed, 6 insertions(+), 3 deletions(-) > > > > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c > > index e184ad4e..df41a3a 100644 > > --- a/fs/f2fs/super.c > > +++ b/fs/f2fs/super.c > > @@ -1058,9 +1058,6 @@ static void f2fs_put_super(struct super_block *sb) > > f2fs_write_checkpoint(sbi, ); > > } > > > > - /* f2fs_write_checkpoint can update stat informaion */ > > - f2fs_destroy_stats(sbi); > > The code order in error path of fill_super is almost the same as the one of > put_super, could you please check that as well? > Thanks Chao, for pointing it out. Yes, the same issue exists in error path of fill_super as well. I will fix it. > Thanks, > > > - > > /* > > * normally superblock is clean, so we need to release this. > > * In addition, EIO will skip do checkpoint, we need this as well. > > @@ -1080,6 +1077,12 @@ static void f2fs_put_super(struct super_block *sb) > > iput(sbi->node_inode); > > iput(sbi->meta_inode); > > > > + /* > > +* iput() can update stat information, if f2fs_write_checkpoint() > > +* above failed with error. > > +*/ > > + f2fs_destroy_stats(sbi); > > + > > /* destroy f2fs internal modules */ > > f2fs_destroy_node_manager(sbi); > > f2fs_destroy_segment_manager(sbi); > > > -- -- Sent by a consultant of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
Re: [PATCH] f2fs: fix use-after-free issue with sbi->stat_info
On 2018/12/24 21:06, Sahitya Tummala wrote: > iput() on sbi->node_inode can update sbi->stat_info > in the below context, if the f2fs_write_checkpoint() > has failed with error. > > f2fs_balance_fs_bg+0x1ac/0x1ec > f2fs_write_node_pages+0x4c/0x260 > do_writepages+0x80/0xbc > __writeback_single_inode+0xdc/0x4ac > writeback_single_inode+0x9c/0x144 > write_inode_now+0xc4/0xec > iput+0x194/0x22c > f2fs_put_super+0x11c/0x1e8 > generic_shutdown_super+0x70/0xf4 > kill_block_super+0x2c/0x5c > kill_f2fs_super+0x44/0x50 > deactivate_locked_super+0x60/0x8c > deactivate_super+0x68/0x74 > cleanup_mnt+0x40/0x78 > > Fix this by moving f2fs_destroy_stats() further below iput(). > > Signed-off-by: Sahitya Tummala > --- > fs/f2fs/super.c | 9 ++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c > index e184ad4e..df41a3a 100644 > --- a/fs/f2fs/super.c > +++ b/fs/f2fs/super.c > @@ -1058,9 +1058,6 @@ static void f2fs_put_super(struct super_block *sb) > f2fs_write_checkpoint(sbi, ); > } > > - /* f2fs_write_checkpoint can update stat informaion */ > - f2fs_destroy_stats(sbi); The code order in error path of fill_super is almost the same as the one of put_super, could you please check that as well? Thanks, > - > /* >* normally superblock is clean, so we need to release this. >* In addition, EIO will skip do checkpoint, we need this as well. > @@ -1080,6 +1077,12 @@ static void f2fs_put_super(struct super_block *sb) > iput(sbi->node_inode); > iput(sbi->meta_inode); > > + /* > + * iput() can update stat information, if f2fs_write_checkpoint() > + * above failed with error. > + */ > + f2fs_destroy_stats(sbi); > + > /* destroy f2fs internal modules */ > f2fs_destroy_node_manager(sbi); > f2fs_destroy_segment_manager(sbi); >
[PATCH] f2fs: fix use-after-free issue with sbi->stat_info
iput() on sbi->node_inode can update sbi->stat_info in the below context, if the f2fs_write_checkpoint() has failed with error. f2fs_balance_fs_bg+0x1ac/0x1ec f2fs_write_node_pages+0x4c/0x260 do_writepages+0x80/0xbc __writeback_single_inode+0xdc/0x4ac writeback_single_inode+0x9c/0x144 write_inode_now+0xc4/0xec iput+0x194/0x22c f2fs_put_super+0x11c/0x1e8 generic_shutdown_super+0x70/0xf4 kill_block_super+0x2c/0x5c kill_f2fs_super+0x44/0x50 deactivate_locked_super+0x60/0x8c deactivate_super+0x68/0x74 cleanup_mnt+0x40/0x78 Fix this by moving f2fs_destroy_stats() further below iput(). Signed-off-by: Sahitya Tummala --- fs/f2fs/super.c | 9 ++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index e184ad4e..df41a3a 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1058,9 +1058,6 @@ static void f2fs_put_super(struct super_block *sb) f2fs_write_checkpoint(sbi, ); } - /* f2fs_write_checkpoint can update stat informaion */ - f2fs_destroy_stats(sbi); - /* * normally superblock is clean, so we need to release this. * In addition, EIO will skip do checkpoint, we need this as well. @@ -1080,6 +1077,12 @@ static void f2fs_put_super(struct super_block *sb) iput(sbi->node_inode); iput(sbi->meta_inode); + /* +* iput() can update stat information, if f2fs_write_checkpoint() +* above failed with error. +*/ + f2fs_destroy_stats(sbi); + /* destroy f2fs internal modules */ f2fs_destroy_node_manager(sbi); f2fs_destroy_segment_manager(sbi); -- Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
