Re: [PATCH v3] ext4: fix bug in extents parsing when eh_entries == 0 and eh_depth > 0

From: kernel test robot
Date: Fri Aug 12 2022 - 16:12:07 EST


Hi "Luís,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on tytso-ext4/dev]
[also build test ERROR on linus/master v5.19 next-20220812]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Lu-s-Henriques/ext4-fix-bug-in-extents-parsing-when-eh_entries-0-and-eh_depth-0/20220812-221443
base: https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev
config: arm64-buildonly-randconfig-r002-20220812 (https://download.01.org/0day-ci/archive/20220813/202208130421.BZpzWWRK-lkp@xxxxxxxxx/config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 5f1c7e2cc5a3c07cbc2412e851a7283c1841f520)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm64 cross compiling tool for clang build
# apt-get install binutils-aarch64-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/ef3617646de6e939d29961099c7c8adcaa0d9fd9
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Lu-s-Henriques/ext4-fix-bug-in-extents-parsing-when-eh_entries-0-and-eh_depth-0/20220812-221443
git checkout ef3617646de6e939d29961099c7c8adcaa0d9fd9
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash fs/ext4/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All errors (new ones prefixed by >>):

>> fs/ext4/extents.c:463:41: error: use of undeclared identifier 'eh_depth'; did you mean 'ext_depth'?
if (unlikely((eh->eh_entries == 0) && (eh_depth > 0))) {
^~~~~~~~
ext_depth
include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^
fs/ext4/ext4_extents.h:192:30: note: 'ext_depth' declared here
static inline unsigned short ext_depth(struct inode *inode)
^
1 error generated.


vim +463 fs/ext4/extents.c

434
435 static int __ext4_ext_check(const char *function, unsigned int line,
436 struct inode *inode, struct ext4_extent_header *eh,
437 int depth, ext4_fsblk_t pblk, ext4_lblk_t lblk)
438 {
439 const char *error_msg;
440 int max = 0, err = -EFSCORRUPTED;
441
442 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
443 error_msg = "invalid magic";
444 goto corrupted;
445 }
446 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
447 error_msg = "unexpected eh_depth";
448 goto corrupted;
449 }
450 if (unlikely(eh->eh_max == 0)) {
451 error_msg = "invalid eh_max";
452 goto corrupted;
453 }
454 max = ext4_ext_max_entries(inode, depth);
455 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
456 error_msg = "too large eh_max";
457 goto corrupted;
458 }
459 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
460 error_msg = "invalid eh_entries";
461 goto corrupted;
462 }
> 463 if (unlikely((eh->eh_entries == 0) && (eh_depth > 0))) {
464 error_msg = "eh_entries is 0 but eh_depth is > 0";
465 goto corrupted;
466 }
467 if (!ext4_valid_extent_entries(inode, eh, lblk, &pblk, depth)) {
468 error_msg = "invalid extent entries";
469 goto corrupted;
470 }
471 if (unlikely(depth > 32)) {
472 error_msg = "too large eh_depth";
473 goto corrupted;
474 }
475 /* Verify checksum on non-root extent tree nodes */
476 if (ext_depth(inode) != depth &&
477 !ext4_extent_block_csum_verify(inode, eh)) {
478 error_msg = "extent tree corrupted";
479 err = -EFSBADCRC;
480 goto corrupted;
481 }
482 return 0;
483
484 corrupted:
485 ext4_error_inode_err(inode, function, line, 0, -err,
486 "pblk %llu bad header/extent: %s - magic %x, "
487 "entries %u, max %u(%u), depth %u(%u)",
488 (unsigned long long) pblk, error_msg,
489 le16_to_cpu(eh->eh_magic),
490 le16_to_cpu(eh->eh_entries),
491 le16_to_cpu(eh->eh_max),
492 max, le16_to_cpu(eh->eh_depth), depth);
493 return err;
494 }
495

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