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[ Upstream commit bf617f7a92edc6bb2909db2bfa4576f50b280ee5 ] If noextent_cache mount option is on, we will never initialize extent tree in inode, but still we're going to access it in f2fs_drop_extent_tree, result in kernel panic as below: BUG: unable to handle kernel NULL pointer dereference at 0000000000000038 IP: _raw_write_lock+0xc/0x30 Call Trace: ? f2fs_drop_extent_tree+0x41/0x70 [f2fs] f2fs_fallocate+0x5a0/0xdd0 [f2fs] ? common_file_perm+0x47/0xc0 ? apparmor_file_permission+0x1a/0x20 vfs_fallocate+0x15b/0x290 SyS_fallocate+0x44/0x70 do_syscall_64+0x6e/0x160 entry_SYSCALL64_slow_path+0x25/0x25 This patch fixes to check extent cache status before using in f2fs_drop_extent_tree. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.