fs/partitions/ldm.c: fix oops caused by corrupted partition table (c340b1d6) · Commits · 戴 / test

The kernel automatically evaluates partition tables of storage devices. The code for evaluating LDM partitions (in fs/partitions/ldm.c) contains a bug that causes a kernel oops on certain corrupted LDM partitions. A kernel subsystem seems to crash, because, after the oops, the kernel no longer recognizes newly connected storage devices. The patch validates the value of vblk_size. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:

Timo Warns <warns@pre-sense.de> Cc: Eugene Teo <eugeneteo@kernel.sg> Cc: Harvey Harrison <harvey.harrison@gmail.com> Cc: Richard Russon <rich@flatcap.org> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

fs/partitions/ldm.c

+12 −4

Original line number	Diff line number	Diff line
		@@ -1299,6 +1299,11 @@ static bool ldm_frag_add (const u8 data, int size, struct list_head frags)

		BUG_ON (!data \|\| !frags);

		if (size < 2 * VBLK_SIZE_HEAD) {
		ldm_error("Value of size is to small.");
		return false;
		}

		group = get_unaligned_be32(data + 0x08);
		rec = get_unaligned_be16(data + 0x0C);
		num = get_unaligned_be16(data + 0x0E);
		@@ -1306,6 +1311,10 @@ static bool ldm_frag_add (const u8 data, int size, struct list_head frags)
		ldm_error ("A VBLK claims to have %d parts.", num);
		return false;
		}
		if (rec >= num) {
		ldm_error("REC value (%d) exceeds NUM value (%d)", rec, num);
		return false;
		}

		list_for_each (item, frags) {
		f = list_entry (item, struct frag, list);
		@@ -1334,10 +1343,9 @@ found:

		f->map \|= (1 << rec);

		if (num > 0) {
		data += VBLK_SIZE_HEAD;
		size -= VBLK_SIZE_HEAD;
		}

		memcpy (f->data+rec*(size-VBLK_SIZE_HEAD)+VBLK_SIZE_HEAD, data, size);

		return true;

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