target/linux/generic/pending-5.15/130-binfmt_elf-dynamically-allocate-note.data-in-parse_e.patch

   1 From ca71e00839fcdd26f122fb6d9e97903c9fe198f7 Mon Sep 17 00:00:00 2001
   2 From: Christian Marangi <ansuelsmth@gmail.com>
   3 Date: Sat, 6 May 2023 08:08:35 +0200
   4 Subject: [PATCH] binfmt_elf: dynamically allocate note.data in
   5  parse_elf_properties
   6
   7 Dynamically allocate note.data in parse_elf_properties to fix
   8 compilation warning on some arch.
   9
  10 On some arch note.data exceet the stack limit for a single function and
  11 this cause the following compilation warning:
  12 fs/binfmt_elf.c: In function 'parse_elf_properties.isra':
  13 fs/binfmt_elf.c:821:1: error: the frame size of 1040 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
  14   821 | }
  15       | ^
  16 cc1: all warnings being treated as errors
  17
  18 Fix this by dynamically allocating the array.
  19
  20 Fixes: 00e19ceec80b ("ELF: Add ELF program property parsing support")
  21 Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  22 Cc: stable@vger.kernel.org # v5.8+
  23 ---
  24  fs/binfmt_elf.c | 32 +++++++++++++++++++++++---------
  25  1 file changed, 23 insertions(+), 9 deletions(-)
  26
  27 --- a/fs/binfmt_elf.c
  28 +++ b/fs/binfmt_elf.c
  29 @@ -768,7 +768,7 @@ static int parse_elf_properties(struct f
  30  {
  31         union {
  32                 struct elf_note nhdr;
  33 -               char data[NOTE_DATA_SZ];
  34 +               char *data;
  35         } note;
  36         loff_t pos;
  37         ssize_t n;
  38 @@ -788,26 +788,38 @@ static int parse_elf_properties(struct f
  39         if (phdr->p_filesz > sizeof(note))
  40                 return -ENOEXEC;
  41
  42 +       note.data = kcalloc(NOTE_DATA_SZ, sizeof(*note.data), GFP_KERNEL);
  43 +       if (!note.data)
  44 +               return -ENOMEM;
  45 +
  46         pos = phdr->p_offset;
  47         n = kernel_read(f, &note, phdr->p_filesz, &pos);
  48
  49         BUILD_BUG_ON(sizeof(note) < sizeof(note.nhdr) + NOTE_NAME_SZ);
  50 -       if (n < 0 || n < sizeof(note.nhdr) + NOTE_NAME_SZ)
  51 -               return -EIO;
  52 +       if (n < 0 || n < sizeof(note.nhdr) + NOTE_NAME_SZ) {
  53 +               ret = -EIO;
  54 +               goto exit;
  55 +       }
  56
  57         if (note.nhdr.n_type != NT_GNU_PROPERTY_TYPE_0 ||
  58             note.nhdr.n_namesz != NOTE_NAME_SZ ||
  59             strncmp(note.data + sizeof(note.nhdr),
  60 -                   GNU_PROPERTY_TYPE_0_NAME, n - sizeof(note.nhdr)))
  61 -               return -ENOEXEC;
  62 +                   GNU_PROPERTY_TYPE_0_NAME, n - sizeof(note.nhdr))) {
  63 +               ret = -ENOEXEC;
  64 +               goto exit;
  65 +       }
  66
  67         off = round_up(sizeof(note.nhdr) + NOTE_NAME_SZ,
  68                        ELF_GNU_PROPERTY_ALIGN);
  69 -       if (off > n)
  70 -               return -ENOEXEC;
  71 -
  72 -       if (note.nhdr.n_descsz > n - off)
  73 -               return -ENOEXEC;
  74 +       if (off > n) {
  75 +               ret = -ENOEXEC;
  76 +               goto exit;
  77 +       }
  78 +
  79 +       if (note.nhdr.n_descsz > n - off) {
  80 +               ret = -ENOEXEC;
  81 +               goto exit;
  82 +       }
  83         datasz = off + note.nhdr.n_descsz;
  84
  85         have_prev_type = false;
  86 @@ -817,6 +829,8 @@ static int parse_elf_properties(struct f
  87                 have_prev_type = true;
  88         } while (!ret);
  89
  90 +exit:
  91 +       kfree(note.data);
  92         return ret == -ENOENT ? 0 : ret;
  93  }
  94