On 2020/12/22 17:32, Weichao Guo wrote:
On 2020/12/22 16:24, Chao Yu wrote:
On 2020/12/14 11:54, Weichao Guo wrote:
We should update the ~S_IRWXUGO part of inode->i_mode in __setattr_copy,
because posix_acl_update_mode updates mode based on inode->i_mode,
which finally overwrites the ~S_IRWXUGO part of i_acl_mode with old
i_mode.
Testcase to reproduce this bug:
0. adduser abc
1. mkfs.f2fs /dev/sdd
2. mount -t f2fs /dev/sdd /mnt/f2fs
3. mkdir /mnt/f2fs/test
4. setfacl -m u:abc:r /mnt/f2fs/test
5. chmod +s /mnt/f2fs/test
Signed-off-by: Weichao Guo <[email protected]>
Signed-off-by: Bin Shu <[email protected]>
---
fs/f2fs/file.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 16ea10f..4d355f9 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -850,6 +850,7 @@ static void __setattr_copy(struct inode *inode,
const struct iattr *attr)
if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
mode &= ~S_ISGID;
+ inode->i_mode = (inode->i_mode & S_IRWXUGO) | (mode &
~S_IRWXUGO);
Sorry, I still have problem with this patch.
I think this equals to inode->i_mode = mode;
Because in chmod_common(), @mode was assigned as:
newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
Hi Chao,
I think this means all bits of S_IALLUGO can be changed during chmod(),
and i_acl_mode has
Hi Weichao,
Correct,
new S_IRWXUGO bits , i_mode has old S_IRWXUGO bits.
Look into acl related code again, I found what f2fs now do is trying to
update i_mode and acl xattr entry atomically, so in advance updated mode
will be record to i_acl_mode, and finally, it will update i_mode w/ i_acl_mode
while acl entry update in path of f2fs_set_acl() - f2fs_setxattr().
In order to keep this rule, I think we need to change as below, let me know
if I missed something.
From: Weichao Guo <[email protected]>
Subject: [PATCH] f2fs: fix to set inode->i_mode correctly for
posix_acl_update_mode
---
fs/f2fs/acl.c | 23 ++++++++++++++++++++++-
fs/f2fs/xattr.c | 15 +++++++++------
2 files changed, 31 insertions(+), 7 deletions(-)
diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
index 1e5e9b1136ee..732ec10e7890 100644
--- a/fs/f2fs/acl.c
+++ b/fs/f2fs/acl.c
@@ -200,6 +200,27 @@ struct posix_acl *f2fs_get_acl(struct inode *inode, int
type)
return __f2fs_get_acl(inode, type, NULL);
}
+static int f2fs_acl_update_mode(struct inode *inode, umode_t *mode_p,
+ struct posix_acl **acl)
+{
+ umode_t mode = inode->i_mode;
+ int error;
+
+ if (is_inode_flag_set(inode, FI_ACL_MODE))
+ mode = F2FS_I(inode)->i_acl_mode;
+
+ error = posix_acl_equiv_mode(*acl, &mode);
+ if (error < 0)
+ return error;
+ if (error == 0)
+ *acl = NULL;
+ if (!in_group_p(inode->i_gid) &&
+ !capable_wrt_inode_uidgid(inode, CAP_FSETID))
+ mode &= ~S_ISGID;
+ *mode_p = mode;
+ return 0;
+}
+
static int __f2fs_set_acl(struct inode *inode, int type,
struct posix_acl *acl, struct page *ipage)
{
@@ -213,7 +234,7 @@ static int __f2fs_set_acl(struct inode *inode, int type,
case ACL_TYPE_ACCESS:
name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
if (acl && !ipage) {
- error = posix_acl_update_mode(inode, &mode, &acl);
+ error = f2fs_acl_update_mode(inode, &mode, &acl);
if (error)
return error;
set_acl_inode(inode, mode);
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index 65afcc3cc68a..2086bef6c154 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -673,7 +673,7 @@ static int __f2fs_setxattr(struct inode *inode, int index,
}
if (value && f2fs_xattr_value_same(here, value, size))
- goto exit;
+ goto same;
} else if ((flags & XATTR_REPLACE)) {
error = -ENODATA;
goto exit;
@@ -738,17 +738,20 @@ static int __f2fs_setxattr(struct inode *inode, int index,
if (error)
goto exit;
- if (is_inode_flag_set(inode, FI_ACL_MODE)) {
- inode->i_mode = F2FS_I(inode)->i_acl_mode;
- inode->i_ctime = current_time(inode);
- clear_inode_flag(inode, FI_ACL_MODE);
- }
if (index == F2FS_XATTR_INDEX_ENCRYPTION &&
!strcmp(name, F2FS_XATTR_NAME_ENCRYPTION_CONTEXT))
f2fs_set_encrypted_inode(inode);
f2fs_mark_inode_dirty_sync(inode, true);
if (!error && S_ISDIR(inode->i_mode))
set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_CP);
+
+same:
+ if (is_inode_flag_set(inode, FI_ACL_MODE)) {
+ inode->i_mode = F2FS_I(inode)->i_acl_mode;
+ inode->i_ctime = current_time(inode);
+ clear_inode_flag(inode, FI_ACL_MODE);
+ }
+
exit:
kfree(base_addr);
return error;
--
2.29.2
BR,
Weichao
and only S_ISUID and S_ISGID bits of newattrs.ia_mode can be changed
during chmod()
That's why setattr_copy() in fs/attr.c just uses "inode->i_mode = mode;"
set_acl_inode(inode, mode);
Another problem is if i_acl_mode is used for error path handling, here
i_acl_mode
and i_mode have the same value, that's not correct?
Jaegeuk,
IIUC, i_acl_mode was introduced for i_mode recovery once acl progress
fails?
Thanks,
}
}
.
_______________________________________________
Linux-f2fs-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
