From ee74cf16b5aa98fc210da23ba3a6c64d5a63289d Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Wed, 17 Mar 2010 13:32:52 -0400 Subject: [PATCH] e2fsck: Fix segmentation fault when checking a file system If a corrupted file system causes us to want to delete an extent, and that causes us to want to release a block in e2fsck pass #1, it would be preferable if e2fsck didn't seg fault. This tends to get users craky, as users are wont to do. :-) Thanks to Dirk Reiners for reporting this bug: e2fsck crashes fixing a corrupted 3.5 TB filesystem: 0x0000000000432002 in ext2fs_unmark_generic_bitmap (bitmap=0x0, bitno=623386749) at gen_bitmap.c:183 183 if ((bitno < bitmap->start) || (bitno > bitmap->end)) { (gdb) bt bitno=623386749) at gen_bitmap.c:183 block=623386749) at ../../lib/ext2fs/bitops.h:319 inuse=-1) at alloc_stats.c:78 extent.c:1509 pb=0x7fffffffdfe0, start_block=0, ehandle=0x6dcf50) at pass1.c:1709 pb=0x7fffffffdfe0, start_block=0, ehandle=0x6dcf50) at pass1.c:1737 pctx=0x7fffffffe100, pb=0x7fffffffdfe0) at pass1.c:1842 block_buf=0x6c4330 "\373\212#") at pass1.c:1920 The source of the NULL bitmap is fs on stack frame 2: (gdb) up 2 inuse=-1) at alloc_stats.c:78 78 ext2fs_unmark_block_bitmap(fs->block_map, blk); Addresses-SourceForge-Bug: #2971800 Signed-off-by: "Theodore Ts'o" --- e2fsck/pass1.c | 1 + 1 file changed, 1 insertion(+) diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c index 0d4c315..5e2ecc7 100644 --- a/e2fsck/pass1.c +++ b/e2fsck/pass1.c @@ -1710,6 +1710,7 @@ static void scan_extent_node(e2fsck_t ctx, struct problem_context *pctx, pctx->blk2 = extent.e_lblk; pctx->num = extent.e_len; if (fix_problem(ctx, problem, pctx)) { + e2fsck_read_bitmaps(ctx); pctx->errcode = ext2fs_extent_delete(ehandle, 0); if (pctx->errcode) { -- 1.8.3.1