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    Subject[PATCH 4.19 007/187] f2fs: fix to adapt small inline xattr space in __find_inline_xattr()
    Date
    4.19-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    [ Upstream commit 2c28aba8b2e2a51749fa66e01b68e1cd5b53e022 ]

    With below testcase, we will fail to find existed xattr entry:

    1. mkfs.f2fs -O extra_attr -O flexible_inline_xattr /dev/zram0
    2. mount -t f2fs -o inline_xattr_size=1 /dev/zram0 /mnt/f2fs/
    3. touch /mnt/f2fs/file
    4. setfattr -n "user.name" -v 0 /mnt/f2fs/file
    5. getfattr -n "user.name" /mnt/f2fs/file

    /mnt/f2fs/file: user.name: No such attribute

    The reason is for inode which has very small inline xattr size,
    __find_inline_xattr() will fail to traverse any entry due to first
    entry may not be loaded from xattr node yet, later, we may skip to
    check entire xattr datas in __find_xattr(), result in such wrong
    condition.

    This patch adds condition to check such case to avoid this issue.

    Signed-off-by: Chao Yu <yuchao0@huawei.com>
    Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    fs/f2fs/xattr.c | 13 ++++++++++---
    1 file changed, 10 insertions(+), 3 deletions(-)

    diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
    index 087e53a2d96c..409a637f7a92 100644
    --- a/fs/f2fs/xattr.c
    +++ b/fs/f2fs/xattr.c
    @@ -227,11 +227,11 @@ static struct f2fs_xattr_entry *__find_inline_xattr(struct inode *inode,
    {
    struct f2fs_xattr_entry *entry;
    unsigned int inline_size = inline_xattr_size(inode);
    + void *max_addr = base_addr + inline_size;

    list_for_each_xattr(entry, base_addr) {
    - if ((void *)entry + sizeof(__u32) > base_addr + inline_size ||
    - (void *)XATTR_NEXT_ENTRY(entry) + sizeof(__u32) >
    - base_addr + inline_size) {
    + if ((void *)entry + sizeof(__u32) > max_addr ||
    + (void *)XATTR_NEXT_ENTRY(entry) > max_addr) {
    *last_addr = entry;
    return NULL;
    }
    @@ -242,6 +242,13 @@ static struct f2fs_xattr_entry *__find_inline_xattr(struct inode *inode,
    if (!memcmp(entry->e_name, name, len))
    break;
    }
    +
    + /* inline xattr header or entry across max inline xattr size */
    + if (IS_XATTR_LAST_ENTRY(entry) &&
    + (void *)entry + sizeof(__u32) > max_addr) {
    + *last_addr = entry;
    + return NULL;
    + }
    return entry;
    }

    --
    2.19.1


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