5.4-stable review patch. If anyone has any objections, please let me know.
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From: Christian Brauner brauner@kernel.org
commit 890ed45bde808c422c3c27d3285fc45affa0f930 upstream.
There's no point in allowing anything kernel internal nor procfs or sysfs.
Link: https://lore.kernel.org/r/20250127091811.3183623-1-quzicheng@huawei.com Link: https://lore.kernel.org/r/20250211-work-acct-v1-2-1c16aecab8b3@kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Amir Goldstein amir73il@gmail.com Reported-by: Zicheng Qu quzicheng@huawei.com Cc: stable@vger.kernel.org Signed-off-by: Christian Brauner brauner@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/acct.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
--- a/kernel/acct.c +++ b/kernel/acct.c @@ -216,6 +216,20 @@ static int acct_on(struct filename *path return -EACCES; }
+ /* Exclude kernel kernel internal filesystems. */ + if (file_inode(file)->i_sb->s_flags & (SB_NOUSER | SB_KERNMOUNT)) { + kfree(acct); + filp_close(file, NULL); + return -EINVAL; + } + + /* Exclude procfs and sysfs. */ + if (file_inode(file)->i_sb->s_iflags & SB_I_USERNS_VISIBLE) { + kfree(acct); + filp_close(file, NULL); + return -EINVAL; + } + if (!(file->f_mode & FMODE_CAN_WRITE)) { kfree(acct); filp_close(file, NULL);