From: Jaegeuk Kim <jaegeuk@kernel.org>
To: linux-f2fs-devel@lists.sourceforge.net
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Subject: [PATCH] fsck.f2fs: fix stack overflow when reading out nat block
Date: Fri, 20 Apr 2018 19:15:46 -0700 [thread overview]
Message-ID: <20180421021546.73327-1-jaegeuk@kernel.org> (raw)
The size of nat_block is less then 4KB, resulting in stack overflow by dev_read.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
fsck/mount.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/fsck/mount.c b/fsck/mount.c
index b374b46..7e936dc 100644
--- a/fsck/mount.c
+++ b/fsck/mount.c
@@ -907,7 +907,7 @@ static int f2fs_init_nid_bitmap(struct f2fs_sb_info *sbi)
struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
struct f2fs_summary_block *sum = curseg->sum_blk;
struct f2fs_journal *journal = &sum->journal;
- struct f2fs_nat_block nat_block;
+ struct f2fs_nat_block *nat_block;
block_t start_blk;
nid_t nid;
int i;
@@ -922,18 +922,22 @@ static int f2fs_init_nid_bitmap(struct f2fs_sb_info *sbi)
/* arbitrarily set 0 bit */
f2fs_set_bit(0, nm_i->nid_bitmap);
- memset((void *)&nat_block, 0, sizeof(struct f2fs_nat_block));
+ nat_block = malloc(F2FS_BLKSIZE);
+ if (!nat_block) {
+ free(nm_i->nid_bitmap);
+ return -ENOMEM;
+ }
for (nid = 0; nid < nm_i->max_nid; nid++) {
if (!(nid % NAT_ENTRY_PER_BLOCK)) {
int ret;
start_blk = current_nat_addr(sbi, nid);
- ret = dev_read_block((void *)&nat_block, start_blk);
+ ret = dev_read_block(nat_block, start_blk);
ASSERT(ret >= 0);
}
- if (nat_block.entries[nid % NAT_ENTRY_PER_BLOCK].block_addr)
+ if (nat_block->entries[nid % NAT_ENTRY_PER_BLOCK].block_addr)
f2fs_set_bit(nid, nm_i->nid_bitmap);
}
@@ -945,6 +949,7 @@ static int f2fs_init_nid_bitmap(struct f2fs_sb_info *sbi)
if (addr != NULL_ADDR)
f2fs_set_bit(nid, nm_i->nid_bitmap);
}
+ free(nat_block);
return 0;
}
--
2.17.0.484.g0c8726318c-goog
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next reply other threads:[~2018-04-21 2:15 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-21 2:15 Jaegeuk Kim [this message]
2018-04-23 7:44 ` [PATCH] fsck.f2fs: fix stack overflow when reading out nat block Chao Yu
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