[PATCH AUTOSEL 6.14 04/15] btrfs: compression: adjust cb->compressed_folios allocation type

[PATCH AUTOSEL 6.14 04/15] btrfs: compression: adjust cb->compressed_folios allocation type

[Sasha Levin]

From: Kees Cook <kees@kernel.org>

[ Upstream commit 6f9a8ab796c6528d22de3c504c81fce7dde63d8a ]

In preparation for making the kmalloc() family of allocators type aware,
we need to make sure that the returned type from the allocation matches
the type of the variable being assigned. (Before, the allocator would
always return "void *", which can be implicitly cast to any pointer type.)

The assigned type is "struct folio **" but the returned type will be
"struct page **". These are the same allocation size (pointer size), but
the types don't match. Adjust the allocation type to match the assignment.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Kees Cook <kees@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/btrfs/compression.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 0c4d486c3048d..18d2210dc7249 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -606,7 +606,7 @@ void btrfs_submit_compressed_read(struct btrfs_bio *bbio)
 	free_extent_map(em);
 
 	cb->nr_folios = DIV_ROUND_UP(compressed_len, PAGE_SIZE);
-	cb->compressed_folios = kcalloc(cb->nr_folios, sizeof(struct page *), GFP_NOFS);
+	cb->compressed_folios = kcalloc(cb->nr_folios, sizeof(struct folio *), GFP_NOFS);
 	if (!cb->compressed_folios) {
 		ret = BLK_STS_RESOURCE;
 		goto out_free_bio;
-- 
2.39.5

[PATCH AUTOSEL 6.14 05/15] btrfs: correct the order of prelim_ref arguments in btrfs__prelim_ref

[Sasha Levin]

From: Goldwyn Rodrigues <rgoldwyn@suse.de>

[ Upstream commit bc7e0975093567f51be8e1bdf4aa5900a3cf0b1e ]

btrfs_prelim_ref() calls the old and new reference variables in the
incorrect order. This causes a NULL pointer dereference because oldref
is passed as NULL to trace_btrfs_prelim_ref_insert().

Note, trace_btrfs_prelim_ref_insert() is being called with newref as
oldref (and oldref as NULL) on purpose in order to print out
the values of newref.

To reproduce:
echo 1 > /sys/kernel/debug/tracing/events/btrfs/btrfs_prelim_ref_insert/enable

Perform some writeback operations.

Backtrace:
BUG: kernel NULL pointer dereference, address: 0000000000000018
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 115949067 P4D 115949067 PUD 11594a067 PMD 0
 Oops: Oops: 0000 [#1] SMP NOPTI
 CPU: 1 UID: 0 PID: 1188 Comm: fsstress Not tainted 6.15.0-rc2-tester+ #47 PREEMPT(voluntary)  7ca2cef72d5e9c600f0c7718adb6462de8149622
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-2-gc13ff2cd-prebuilt.qemu.org 04/01/2014
 RIP: 0010:trace_event_raw_event_btrfs__prelim_ref+0x72/0x130
 Code: e8 43 81 9f ff 48 85 c0 74 78 4d 85 e4 0f 84 8f 00 00 00 49 8b 94 24 c0 06 00 00 48 8b 0a 48 89 48 08 48 8b 52 08 48 89 50 10 <49> 8b 55 18 48 89 50 18 49 8b 55 20 48 89 50 20 41 0f b6 55 28 88
 RSP: 0018:ffffce44820077a0 EFLAGS: 00010286
 RAX: ffff8c6b403f9014 RBX: ffff8c6b55825730 RCX: 304994edf9cf506b
 RDX: d8b11eb7f0fdb699 RSI: ffff8c6b403f9010 RDI: ffff8c6b403f9010
 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000010
 R10: 00000000ffffffff R11: 0000000000000000 R12: ffff8c6b4e8fb000
 R13: 0000000000000000 R14: ffffce44820077a8 R15: ffff8c6b4abd1540
 FS:  00007f4dc6813740(0000) GS:ffff8c6c1d378000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000018 CR3: 000000010eb42000 CR4: 0000000000750ef0
 PKRU: 55555554
 Call Trace:
  <TASK>
  prelim_ref_insert+0x1c1/0x270
  find_parent_nodes+0x12a6/0x1ee0
  ? __entry_text_end+0x101f06/0x101f09
  ? srso_alias_return_thunk+0x5/0xfbef5
  ? srso_alias_return_thunk+0x5/0xfbef5
  ? srso_alias_return_thunk+0x5/0xfbef5
  ? srso_alias_return_thunk+0x5/0xfbef5
  btrfs_is_data_extent_shared+0x167/0x640
  ? fiemap_process_hole+0xd0/0x2c0
  extent_fiemap+0xa5c/0xbc0
  ? __entry_text_end+0x101f05/0x101f09
  btrfs_fiemap+0x7e/0xd0
  do_vfs_ioctl+0x425/0x9d0
  __x64_sys_ioctl+0x75/0xc0

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/trace/events/btrfs.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index 549ab3b419618..3efc00cc1bcd2 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -1928,7 +1928,7 @@ DECLARE_EVENT_CLASS(btrfs__prelim_ref,
 	TP_PROTO(const struct btrfs_fs_info *fs_info,
 		 const struct prelim_ref *oldref,
 		 const struct prelim_ref *newref, u64 tree_size),
-	TP_ARGS(fs_info, newref, oldref, tree_size),
+	TP_ARGS(fs_info, oldref, newref, tree_size),
 
 	TP_STRUCT__entry_btrfs(
 		__field(	u64,  root_id		)
-- 
2.39.5

[PATCH AUTOSEL 6.14 06/15] btrfs: handle empty eb->folios in num_extent_folios()

[Sasha Levin]

From: Boris Burkov <boris@bur.io>

[ Upstream commit d6fe0c69b3aa5c985380b794bdf8e6e9b1811e60 ]

num_extent_folios() unconditionally calls folio_order() on
eb->folios[0]. If that is NULL this will be a segfault. It is reasonable
for it to return 0 as the number of folios in the eb when the first
entry is NULL, so do that instead.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/btrfs/extent_io.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 6c5328bfabc22..2aefc64cdd295 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -297,6 +297,8 @@ static inline int num_extent_pages(const struct extent_buffer *eb)
  */
 static inline int num_extent_folios(const struct extent_buffer *eb)
 {
+	if (!eb->folios[0])
+		return 0;
 	if (folio_order(eb->folios[0]))
 		return 1;
 	return num_extent_pages(eb);
-- 
2.39.5

[PATCH AUTOSEL 6.14 07/15] btrfs: avoid NULL pointer dereference if no valid csum tree

[Sasha Levin]

From: Qu Wenruo <wqu@suse.com>

[ Upstream commit f95d186255b319c48a365d47b69bd997fecb674e ]

[BUG]
When trying read-only scrub on a btrfs with rescue=idatacsums mount
option, it will crash with the following call trace:

  BUG: kernel NULL pointer dereference, address: 0000000000000208
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  CPU: 1 UID: 0 PID: 835 Comm: btrfs Tainted: G           O        6.15.0-rc3-custom+ #236 PREEMPT(full)
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022
  RIP: 0010:btrfs_lookup_csums_bitmap+0x49/0x480 [btrfs]
  Call Trace:
   <TASK>
   scrub_find_fill_first_stripe+0x35b/0x3d0 [btrfs]
   scrub_simple_mirror+0x175/0x290 [btrfs]
   scrub_stripe+0x5f7/0x6f0 [btrfs]
   scrub_chunk+0x9a/0x150 [btrfs]
   scrub_enumerate_chunks+0x333/0x660 [btrfs]
   btrfs_scrub_dev+0x23e/0x600 [btrfs]
   btrfs_ioctl+0x1dcf/0x2f80 [btrfs]
   __x64_sys_ioctl+0x97/0xc0
   do_syscall_64+0x4f/0x120
   entry_SYSCALL_64_after_hwframe+0x76/0x7e

[CAUSE]
Mount option "rescue=idatacsums" will completely skip loading the csum
tree, so that any data read will not find any data csum thus we will
ignore data checksum verification.

Normally call sites utilizing csum tree will check the fs state flag
NO_DATA_CSUMS bit, but unfortunately scrub does not check that bit at all.

This results in scrub to call btrfs_search_slot() on a NULL pointer
and triggered above crash.

[FIX]
Check both extent and csum tree root before doing any tree search.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/btrfs/scrub.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 531312efee8df..5d0060eb8ff4c 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -1541,8 +1541,8 @@ static int scrub_find_fill_first_stripe(struct btrfs_block_group *bg,
 	u64 extent_gen;
 	int ret;
 
-	if (unlikely(!extent_root)) {
-		btrfs_err(fs_info, "no valid extent root for scrub");
+	if (unlikely(!extent_root || !csum_root)) {
+		btrfs_err(fs_info, "no valid extent or csum root for scrub");
 		return -EUCLEAN;
 	}
 	memset(stripe->sectors, 0, sizeof(struct scrub_sector_verification) *
-- 
2.39.5