git.ipfire.org Git - thirdparty/openwrt.git/blob

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Jan Kara <jack@suse.cz>
   3 Date: Tue, 20 Dec 2022 12:38:45 +0100
   4 Subject: udf: Allocate name buffer in directory iterator on heap
   5
   6 commit 0aba4860b0d0216a1a300484ff536171894d49d8 upstream.
   7
   8 Currently we allocate name buffer in directory iterators (struct
   9 udf_fileident_iter) on stack. These structures are relatively large
  10 (some 360 bytes on 64-bit architectures). For udf_rename() which needs
  11 to keep three of these structures in parallel the stack usage becomes
  12 rather heavy - 1536 bytes in total. Allocate the name buffer in the
  13 iterator from heap to avoid excessive stack usage.
  14
  15 Link: https://lore.kernel.org/all/202212200558.lK9x1KW0-lkp@intel.com
  16 Reported-by: kernel test robot <lkp@intel.com>
  17 Signed-off-by: Jan Kara <jack@suse.cz>
  18 [Add extra include linux/slab.h]
  19 Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
  20 ---
  21  fs/udf/directory.c | 24 ++++++++++++++++--------
  22  fs/udf/udfdecl.h   |  2 +-
  23  2 files changed, 17 insertions(+), 9 deletions(-)
  24
  25 --- a/fs/udf/directory.c
  26 +++ b/fs/udf/directory.c
  27 @@ -19,6 +19,7 @@
  28  #include <linux/bio.h>
  29  #include <linux/crc-itu-t.h>
  30  #include <linux/iversion.h>
  31 +#include <linux/slab.h>
  32
  33  static int udf_verify_fi(struct udf_fileident_iter *iter)
  34  {
  35 @@ -248,9 +249,14 @@ int udf_fiiter_init(struct udf_fileident
  36         iter->elen = 0;
  37         iter->epos.bh = NULL;
  38         iter->name = NULL;
  39 +       iter->namebuf = kmalloc(UDF_NAME_LEN_CS0, GFP_KERNEL);
  40 +       if (!iter->namebuf)
  41 +               return -ENOMEM;
  42
  43 -       if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
  44 -               return udf_copy_fi(iter);
  45 +       if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
  46 +               err = udf_copy_fi(iter);
  47 +               goto out;
  48 +       }
  49
  50         if (inode_bmap(dir, iter->pos >> dir->i_blkbits, &iter->epos,
  51                        &iter->eloc, &iter->elen, &iter->loffset) !=
  52 @@ -260,17 +266,17 @@ int udf_fiiter_init(struct udf_fileident
  53                 udf_err(dir->i_sb,
  54                         "position %llu not allocated in directory (ino %lu)\n",
  55                         (unsigned long long)pos, dir->i_ino);
  56 -               return -EFSCORRUPTED;
  57 +               err = -EFSCORRUPTED;
  58 +               goto out;
  59         }
  60         err = udf_fiiter_load_bhs(iter);
  61         if (err < 0)
  62 -               return err;
  63 +               goto out;
  64         err = udf_copy_fi(iter);
  65 -       if (err < 0) {
  66 +out:
  67 +       if (err < 0)
  68                 udf_fiiter_release(iter);
  69 -               return err;
  70 -       }
  71 -       return 0;
  72 +       return err;
  73  }
  74
  75  int udf_fiiter_advance(struct udf_fileident_iter *iter)
  76 @@ -307,6 +313,8 @@ void udf_fiiter_release(struct udf_filei
  77         brelse(iter->bh[0]);
  78         brelse(iter->bh[1]);
  79         iter->bh[0] = iter->bh[1] = NULL;
  80 +       kfree(iter->namebuf);
  81 +       iter->namebuf = NULL;
  82  }
  83
  84  static void udf_copy_to_bufs(void *buf1, int len1, void *buf2, int len2,
  85 --- a/fs/udf/udfdecl.h
  86 +++ b/fs/udf/udfdecl.h
  87 @@ -99,7 +99,7 @@ struct udf_fileident_iter {
  88         struct extent_position epos;    /* Position after the above extent */
  89         struct fileIdentDesc fi;        /* Copied directory entry */
  90         uint8_t *name;                  /* Pointer to entry name */
  91 -       uint8_t namebuf[UDF_NAME_LEN_CS0]; /* Storage for entry name in case
  92 +       uint8_t *namebuf;               /* Storage for entry name in case
  93                                          * the name is split between two blocks
  94                                          */
  95  };