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author | Chao Yu <yuchao0@huawei.com> | 2021-05-07 18:10:38 +0800 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-19 09:45:03 +0200 |
commit | 86786603014e0a22d0d6af8e80ae4b8687927048 (patch) | |
tree | c6bdec3498b383266c6f9f815fc31c0134e449da | |
parent | 5e4f5138bd8522ebe231a137682d3857209a2c07 (diff) | |
download | kernel_replicant_linux-86786603014e0a22d0d6af8e80ae4b8687927048.tar.gz kernel_replicant_linux-86786603014e0a22d0d6af8e80ae4b8687927048.tar.bz2 kernel_replicant_linux-86786603014e0a22d0d6af8e80ae4b8687927048.zip |
f2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances
commit cad83c968c2ebe97905f900326988ed37146c347 upstream.
As syzbot reported, there is an use-after-free issue during f2fs recovery:
Use-after-free write at 0xffff88823bc16040 (in kfence-#10):
kmem_cache_destroy+0x1f/0x120 mm/slab_common.c:486
f2fs_recover_fsync_data+0x75b0/0x8380 fs/f2fs/recovery.c:869
f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945
mount_bdev+0x26c/0x3a0 fs/super.c:1367
legacy_get_tree+0xea/0x180 fs/fs_context.c:592
vfs_get_tree+0x86/0x270 fs/super.c:1497
do_new_mount fs/namespace.c:2905 [inline]
path_mount+0x196f/0x2be0 fs/namespace.c:3235
do_mount fs/namespace.c:3248 [inline]
__do_sys_mount fs/namespace.c:3456 [inline]
__se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433
do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae
The root cause is multi f2fs filesystem instances can race on accessing
global fsync_entry_slab pointer, result in use-after-free issue of slab
cache, fixes to init/destroy this slab cache only once during module
init/destroy procedure to avoid this issue.
Reported-by: syzbot+9d90dad32dd9727ed084@syzkaller.appspotmail.com
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | fs/f2fs/f2fs.h | 2 | ||||
-rw-r--r-- | fs/f2fs/recovery.c | 23 | ||||
-rw-r--r-- | fs/f2fs/super.c | 8 |
3 files changed, 23 insertions, 10 deletions
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 69a390c6064c..2d7799bd30b1 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -3462,6 +3462,8 @@ void f2fs_destroy_garbage_collection_cache(void); */ int f2fs_recover_fsync_data(struct f2fs_sb_info *sbi, bool check_only); bool f2fs_space_for_roll_forward(struct f2fs_sb_info *sbi); +int __init f2fs_create_recovery_cache(void); +void f2fs_destroy_recovery_cache(void); /* * debug.c diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c index 4f12ade6410a..72ce13111679 100644 --- a/fs/f2fs/recovery.c +++ b/fs/f2fs/recovery.c @@ -777,13 +777,6 @@ int f2fs_recover_fsync_data(struct f2fs_sb_info *sbi, bool check_only) quota_enabled = f2fs_enable_quota_files(sbi, s_flags & SB_RDONLY); #endif - fsync_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_inode_entry", - sizeof(struct fsync_inode_entry)); - if (!fsync_entry_slab) { - err = -ENOMEM; - goto out; - } - INIT_LIST_HEAD(&inode_list); INIT_LIST_HEAD(&tmp_inode_list); INIT_LIST_HEAD(&dir_list); @@ -856,8 +849,6 @@ skip: } } - kmem_cache_destroy(fsync_entry_slab); -out: #ifdef CONFIG_QUOTA /* Turn quotas off */ if (quota_enabled) @@ -867,3 +858,17 @@ out: return ret ? ret: err; } + +int __init f2fs_create_recovery_cache(void) +{ + fsync_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_inode_entry", + sizeof(struct fsync_inode_entry)); + if (!fsync_entry_slab) + return -ENOMEM; + return 0; +} + +void f2fs_destroy_recovery_cache(void) +{ + kmem_cache_destroy(fsync_entry_slab); +} diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index abc469dd9aea..4af02719bb14 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -4027,9 +4027,12 @@ static int __init init_f2fs_fs(void) err = f2fs_create_checkpoint_caches(); if (err) goto free_segment_manager_caches; - err = f2fs_create_extent_cache(); + err = f2fs_create_recovery_cache(); if (err) goto free_checkpoint_caches; + err = f2fs_create_extent_cache(); + if (err) + goto free_recovery_cache; err = f2fs_create_garbage_collection_cache(); if (err) goto free_extent_cache; @@ -4078,6 +4081,8 @@ free_garbage_collection_cache: f2fs_destroy_garbage_collection_cache(); free_extent_cache: f2fs_destroy_extent_cache(); +free_recovery_cache: + f2fs_destroy_recovery_cache(); free_checkpoint_caches: f2fs_destroy_checkpoint_caches(); free_segment_manager_caches: @@ -4103,6 +4108,7 @@ static void __exit exit_f2fs_fs(void) f2fs_exit_sysfs(); f2fs_destroy_garbage_collection_cache(); f2fs_destroy_extent_cache(); + f2fs_destroy_recovery_cache(); f2fs_destroy_checkpoint_caches(); f2fs_destroy_segment_manager_caches(); f2fs_destroy_node_manager_caches(); |