f2fs_inode_info.flags is unsigned long variable, it has 32 bits
in 32bit architecture, since we introduced FI_MMAP_FILE flag
when we support data compression, we may access memory cross
the border of .flags field, corrupting .i_sem field, result in
below deadlock.

To fix this issue, let's expand .flags as an array to grab enough
space to store new flags.

Call Trace:
 __schedule+0x8d0/0x13fc
 ? mark_held_locks+0xac/0x100
 schedule+0xcc/0x260
 rwsem_down_write_slowpath+0x3ab/0x65d
 down_write+0xc7/0xe0
 f2fs_drop_nlink+0x3d/0x600 [f2fs]
 f2fs_delete_inline_entry+0x300/0x440 [f2fs]
 f2fs_delete_entry+0x3a1/0x7f0 [f2fs]
 f2fs_unlink+0x500/0x790 [f2fs]
 vfs_unlink+0x211/0x490
 do_unlinkat+0x483/0x520
 sys_unlink+0x4a/0x70
 do_fast_syscall_32+0x12b/0x683
 entry_SYSENTER_32+0xaa/0x102

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Tested-by: Ondrej Jirman <meg...@megous.com>
Signed-off-by: Chao Yu <yuch...@huawei.com>
---
v5:
- get rid of FI_ARRAY_SIZE
- use bitmap_zero for cleanup
 fs/f2fs/f2fs.h  | 99 ++++++++++++++++++++++++-------------------------
 fs/f2fs/inode.c |  2 +-
 2 files changed, 50 insertions(+), 51 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index fcafa68212eb..2049e258bfbd 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -682,6 +682,44 @@ enum {
        MAX_GC_FAILURE
 };
 
+/* used for f2fs_inode_info->flags */
+enum {
+       FI_NEW_INODE,           /* indicate newly allocated inode */
+       FI_DIRTY_INODE,         /* indicate inode is dirty or not */
+       FI_AUTO_RECOVER,        /* indicate inode is recoverable */
+       FI_DIRTY_DIR,           /* indicate directory has dirty pages */
+       FI_INC_LINK,            /* need to increment i_nlink */
+       FI_ACL_MODE,            /* indicate acl mode */
+       FI_NO_ALLOC,            /* should not allocate any blocks */
+       FI_FREE_NID,            /* free allocated nide */
+       FI_NO_EXTENT,           /* not to use the extent cache */
+       FI_INLINE_XATTR,        /* used for inline xattr */
+       FI_INLINE_DATA,         /* used for inline data*/
+       FI_INLINE_DENTRY,       /* used for inline dentry */
+       FI_APPEND_WRITE,        /* inode has appended data */
+       FI_UPDATE_WRITE,        /* inode has in-place-update data */
+       FI_NEED_IPU,            /* used for ipu per file */
+       FI_ATOMIC_FILE,         /* indicate atomic file */
+       FI_ATOMIC_COMMIT,       /* indicate the state of atomical committing */
+       FI_VOLATILE_FILE,       /* indicate volatile file */
+       FI_FIRST_BLOCK_WRITTEN, /* indicate #0 data block was written */
+       FI_DROP_CACHE,          /* drop dirty page cache */
+       FI_DATA_EXIST,          /* indicate data exists */
+       FI_INLINE_DOTS,         /* indicate inline dot dentries */
+       FI_DO_DEFRAG,           /* indicate defragment is running */
+       FI_DIRTY_FILE,          /* indicate regular/symlink has dirty pages */
+       FI_NO_PREALLOC,         /* indicate skipped preallocated blocks */
+       FI_HOT_DATA,            /* indicate file is hot */
+       FI_EXTRA_ATTR,          /* indicate file has extra attribute */
+       FI_PROJ_INHERIT,        /* indicate file inherits projectid */
+       FI_PIN_FILE,            /* indicate file should not be gced */
+       FI_ATOMIC_REVOKE_REQUEST, /* request to drop atomic data */
+       FI_VERITY_IN_PROGRESS,  /* building fs-verity Merkle tree */
+       FI_COMPRESSED_FILE,     /* indicate file's data can be compressed */
+       FI_MMAP_FILE,           /* indicate file was mmapped */
+       FI_MAX,                 /* max flag, never be used */
+};
+
 struct f2fs_inode_info {
        struct inode vfs_inode;         /* serve a vfs inode */
        unsigned long i_flags;          /* keep an inode flags for ioctl */
@@ -694,7 +732,7 @@ struct f2fs_inode_info {
        umode_t i_acl_mode;             /* keep file acl mode temporarily */
 
        /* Use below internally in f2fs*/
-       unsigned long flags;            /* use to pass per-file flags */
+       unsigned long flags[BITS_TO_LONGS(FI_MAX)];     /* use to pass per-file 
flags */
        struct rw_semaphore i_sem;      /* protect fi info */
        atomic_t dirty_pages;           /* # of dirty pages */
        f2fs_hash_t chash;              /* hash value of given file name */
@@ -2531,43 +2569,6 @@ static inline __u32 f2fs_mask_flags(umode_t mode, __u32 
flags)
                return flags & F2FS_OTHER_FLMASK;
 }
 
-/* used for f2fs_inode_info->flags */
-enum {
-       FI_NEW_INODE,           /* indicate newly allocated inode */
-       FI_DIRTY_INODE,         /* indicate inode is dirty or not */
-       FI_AUTO_RECOVER,        /* indicate inode is recoverable */
-       FI_DIRTY_DIR,           /* indicate directory has dirty pages */
-       FI_INC_LINK,            /* need to increment i_nlink */
-       FI_ACL_MODE,            /* indicate acl mode */
-       FI_NO_ALLOC,            /* should not allocate any blocks */
-       FI_FREE_NID,            /* free allocated nide */
-       FI_NO_EXTENT,           /* not to use the extent cache */
-       FI_INLINE_XATTR,        /* used for inline xattr */
-       FI_INLINE_DATA,         /* used for inline data*/
-       FI_INLINE_DENTRY,       /* used for inline dentry */
-       FI_APPEND_WRITE,        /* inode has appended data */
-       FI_UPDATE_WRITE,        /* inode has in-place-update data */
-       FI_NEED_IPU,            /* used for ipu per file */
-       FI_ATOMIC_FILE,         /* indicate atomic file */
-       FI_ATOMIC_COMMIT,       /* indicate the state of atomical committing */
-       FI_VOLATILE_FILE,       /* indicate volatile file */
-       FI_FIRST_BLOCK_WRITTEN, /* indicate #0 data block was written */
-       FI_DROP_CACHE,          /* drop dirty page cache */
-       FI_DATA_EXIST,          /* indicate data exists */
-       FI_INLINE_DOTS,         /* indicate inline dot dentries */
-       FI_DO_DEFRAG,           /* indicate defragment is running */
-       FI_DIRTY_FILE,          /* indicate regular/symlink has dirty pages */
-       FI_NO_PREALLOC,         /* indicate skipped preallocated blocks */
-       FI_HOT_DATA,            /* indicate file is hot */
-       FI_EXTRA_ATTR,          /* indicate file has extra attribute */
-       FI_PROJ_INHERIT,        /* indicate file inherits projectid */
-       FI_PIN_FILE,            /* indicate file should not be gced */
-       FI_ATOMIC_REVOKE_REQUEST, /* request to drop atomic data */
-       FI_VERITY_IN_PROGRESS,  /* building fs-verity Merkle tree */
-       FI_COMPRESSED_FILE,     /* indicate file's data can be compressed */
-       FI_MMAP_FILE,           /* indicate file was mmapped */
-};
-
 static inline void __mark_inode_dirty_flag(struct inode *inode,
                                                int flag, bool set)
 {
@@ -2588,20 +2589,18 @@ static inline void __mark_inode_dirty_flag(struct inode 
*inode,
 
 static inline void set_inode_flag(struct inode *inode, int flag)
 {
-       if (!test_bit(flag, &F2FS_I(inode)->flags))
-               set_bit(flag, &F2FS_I(inode)->flags);
+       test_and_set_bit(flag, F2FS_I(inode)->flags);
        __mark_inode_dirty_flag(inode, flag, true);
 }
 
 static inline int is_inode_flag_set(struct inode *inode, int flag)
 {
-       return test_bit(flag, &F2FS_I(inode)->flags);
+       return test_bit(flag, F2FS_I(inode)->flags);
 }
 
 static inline void clear_inode_flag(struct inode *inode, int flag)
 {
-       if (test_bit(flag, &F2FS_I(inode)->flags))
-               clear_bit(flag, &F2FS_I(inode)->flags);
+       test_and_clear_bit(flag, F2FS_I(inode)->flags);
        __mark_inode_dirty_flag(inode, flag, false);
 }
 
@@ -2692,19 +2691,19 @@ static inline void get_inline_info(struct inode *inode, 
struct f2fs_inode *ri)
        struct f2fs_inode_info *fi = F2FS_I(inode);
 
        if (ri->i_inline & F2FS_INLINE_XATTR)
-               set_bit(FI_INLINE_XATTR, &fi->flags);
+               set_bit(FI_INLINE_XATTR, fi->flags);
        if (ri->i_inline & F2FS_INLINE_DATA)
-               set_bit(FI_INLINE_DATA, &fi->flags);
+               set_bit(FI_INLINE_DATA, fi->flags);
        if (ri->i_inline & F2FS_INLINE_DENTRY)
-               set_bit(FI_INLINE_DENTRY, &fi->flags);
+               set_bit(FI_INLINE_DENTRY, fi->flags);
        if (ri->i_inline & F2FS_DATA_EXIST)
-               set_bit(FI_DATA_EXIST, &fi->flags);
+               set_bit(FI_DATA_EXIST, fi->flags);
        if (ri->i_inline & F2FS_INLINE_DOTS)
-               set_bit(FI_INLINE_DOTS, &fi->flags);
+               set_bit(FI_INLINE_DOTS, fi->flags);
        if (ri->i_inline & F2FS_EXTRA_ATTR)
-               set_bit(FI_EXTRA_ATTR, &fi->flags);
+               set_bit(FI_EXTRA_ATTR, fi->flags);
        if (ri->i_inline & F2FS_PIN_FILE)
-               set_bit(FI_PIN_FILE, &fi->flags);
+               set_bit(FI_PIN_FILE, fi->flags);
 }
 
 static inline void set_raw_inline(struct inode *inode, struct f2fs_inode *ri)
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 44e08bf2e2b4..fded4b342346 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -362,7 +362,7 @@ static int do_read_inode(struct inode *inode)
        fi->i_flags = le32_to_cpu(ri->i_flags);
        if (S_ISREG(inode->i_mode))
                fi->i_flags &= ~F2FS_PROJINHERIT_FL;
-       fi->flags = 0;
+       bitmap_zero(fi->flags, BITS_TO_LONGS(FI_MAX));
        fi->i_advise = ri->i_advise;
        fi->i_pino = le32_to_cpu(ri->i_pino);
        fi->i_dir_level = ri->i_dir_level;
-- 
2.18.0.rc1



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