| From 4bd9877f62166b7e369773ab92fe24a39f6515f8 Mon Sep 17 00:00:00 2001 |
| From: Sudhakar Kuppusamy <sudhakar@linux.ibm.com> |
| Date: Wed, 6 Apr 2022 18:03:37 +0530 |
| Subject: [PATCH 33/38] fs/f2fs: Do not read past the end of nat journal |
| entries |
| |
| A corrupt f2fs file system could specify a nat journal entry count |
| that is beyond the maximum NAT_JOURNAL_ENTRIES. |
| |
| Check if the specified nat journal entry count before accessing the |
| array, and throw an error if it is too large. |
| |
| Signed-off-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com> |
| Signed-off-by: Daniel Axtens <dja@axtens.net> |
| Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> |
| --- |
| grub-core/fs/f2fs.c | 21 ++++++++++++++------- |
| 1 file changed, 14 insertions(+), 7 deletions(-) |
| |
| diff --git a/grub-core/fs/f2fs.c b/grub-core/fs/f2fs.c |
| index 8a9992ca9..63702214b 100644 |
| --- a/grub-core/fs/f2fs.c |
| +++ b/grub-core/fs/f2fs.c |
| @@ -632,23 +632,27 @@ get_nat_journal (struct grub_f2fs_data *data) |
| return err; |
| } |
| |
| -static grub_uint32_t |
| -get_blkaddr_from_nat_journal (struct grub_f2fs_data *data, grub_uint32_t nid) |
| +static grub_err_t |
| +get_blkaddr_from_nat_journal (struct grub_f2fs_data *data, grub_uint32_t nid, |
| + grub_uint32_t *blkaddr) |
| { |
| grub_uint16_t n = grub_le_to_cpu16 (data->nat_j.n_nats); |
| - grub_uint32_t blkaddr = 0; |
| grub_uint16_t i; |
| |
| + if (n >= NAT_JOURNAL_ENTRIES) |
| + return grub_error (GRUB_ERR_BAD_FS, |
| + "invalid number of nat journal entries"); |
| + |
| for (i = 0; i < n; i++) |
| { |
| if (grub_le_to_cpu32 (data->nat_j.entries[i].nid) == nid) |
| { |
| - blkaddr = grub_le_to_cpu32 (data->nat_j.entries[i].ne.block_addr); |
| + *blkaddr = grub_le_to_cpu32 (data->nat_j.entries[i].ne.block_addr); |
| break; |
| } |
| } |
| |
| - return blkaddr; |
| + return GRUB_ERR_NONE; |
| } |
| |
| static grub_uint32_t |
| @@ -656,10 +660,13 @@ get_node_blkaddr (struct grub_f2fs_data *data, grub_uint32_t nid) |
| { |
| struct grub_f2fs_nat_block *nat_block; |
| grub_uint32_t seg_off, block_off, entry_off, block_addr; |
| - grub_uint32_t blkaddr; |
| + grub_uint32_t blkaddr = 0; |
| grub_err_t err; |
| |
| - blkaddr = get_blkaddr_from_nat_journal (data, nid); |
| + err = get_blkaddr_from_nat_journal (data, nid, &blkaddr); |
| + if (err != GRUB_ERR_NONE) |
| + return 0; |
| + |
| if (blkaddr) |
| return blkaddr; |
| |
| -- |
| 2.37.0.rc0.104.g0611611a94-goog |
| |