--- /dev/null
+From 2dcf5fde6dffb312a4bfb8ef940cea2d1f402e32 Mon Sep 17 00:00:00 2001
+From: Baokun Li <libaokun1@huawei.com>
+Date: Mon, 27 Nov 2023 14:33:13 +0800
+Subject: ext4: prevent the normalized size from exceeding EXT_MAX_BLOCKS
+
+From: Baokun Li <libaokun1@huawei.com>
+
+commit 2dcf5fde6dffb312a4bfb8ef940cea2d1f402e32 upstream.
+
+For files with logical blocks close to EXT_MAX_BLOCKS, the file size
+predicted in ext4_mb_normalize_request() may exceed EXT_MAX_BLOCKS.
+This can cause some blocks to be preallocated that will not be used.
+And after [Fixes], the following issue may be triggered:
+
+=========================================================
+ kernel BUG at fs/ext4/mballoc.c:4653!
+ Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
+ CPU: 1 PID: 2357 Comm: xfs_io 6.7.0-rc2-00195-g0f5cc96c367f
+ Hardware name: linux,dummy-virt (DT)
+ pc : ext4_mb_use_inode_pa+0x148/0x208
+ lr : ext4_mb_use_inode_pa+0x98/0x208
+ Call trace:
+ ext4_mb_use_inode_pa+0x148/0x208
+ ext4_mb_new_inode_pa+0x240/0x4a8
+ ext4_mb_use_best_found+0x1d4/0x208
+ ext4_mb_try_best_found+0xc8/0x110
+ ext4_mb_regular_allocator+0x11c/0xf48
+ ext4_mb_new_blocks+0x790/0xaa8
+ ext4_ext_map_blocks+0x7cc/0xd20
+ ext4_map_blocks+0x170/0x600
+ ext4_iomap_begin+0x1c0/0x348
+=========================================================
+
+Here is a calculation when adjusting ac_b_ex in ext4_mb_new_inode_pa():
+
+ ex.fe_logical = orig_goal_end - EXT4_C2B(sbi, ex.fe_len);
+ if (ac->ac_o_ex.fe_logical >= ex.fe_logical)
+ goto adjust_bex;
+
+The problem is that when orig_goal_end is subtracted from ac_b_ex.fe_len
+it is still greater than EXT_MAX_BLOCKS, which causes ex.fe_logical to
+overflow to a very small value, which ultimately triggers a BUG_ON in
+ext4_mb_new_inode_pa() because pa->pa_free < len.
+
+The last logical block of an actual write request does not exceed
+EXT_MAX_BLOCKS, so in ext4_mb_normalize_request() also avoids normalizing
+the last logical block to exceed EXT_MAX_BLOCKS to avoid the above issue.
+
+The test case in [Link] can reproduce the above issue with 64k block size.
+
+Link: https://patchwork.kernel.org/project/fstests/list/?series=804003
+Cc: <stable@kernel.org> # 6.4
+Fixes: 93cdf49f6eca ("ext4: Fix best extent lstart adjustment logic in ext4_mb_new_inode_pa()")
+Signed-off-by: Baokun Li <libaokun1@huawei.com>
+Reviewed-by: Jan Kara <jack@suse.cz>
+Link: https://lore.kernel.org/r/20231127063313.3734294-1-libaokun1@huawei.com
+Signed-off-by: Theodore Ts'o <tytso@mit.edu>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/ext4/mballoc.c | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+--- a/fs/ext4/mballoc.c
++++ b/fs/ext4/mballoc.c
+@@ -3181,6 +3181,10 @@ ext4_mb_normalize_request(struct ext4_al
+ start = max(start, rounddown(ac->ac_o_ex.fe_logical,
+ (ext4_lblk_t)EXT4_BLOCKS_PER_GROUP(ac->ac_sb)));
+
++ /* avoid unnecessary preallocation that may trigger assertions */
++ if (start + size > EXT_MAX_BLOCKS)
++ size = EXT_MAX_BLOCKS - start;
++
+ /* don't cover already allocated blocks in selected range */
+ if (ar->pleft && start <= ar->lleft) {
+ size -= ar->lleft + 1 - start;
--- /dev/null
+From 7e2c1e4b34f07d9aa8937fab88359d4a0fce468e Mon Sep 17 00:00:00 2001
+From: Mark Rutland <mark.rutland@arm.com>
+Date: Fri, 15 Dec 2023 11:24:50 +0000
+Subject: perf: Fix perf_event_validate_size() lockdep splat
+
+From: Mark Rutland <mark.rutland@arm.com>
+
+commit 7e2c1e4b34f07d9aa8937fab88359d4a0fce468e upstream.
+
+When lockdep is enabled, the for_each_sibling_event(sibling, event)
+macro checks that event->ctx->mutex is held. When creating a new group
+leader event, we call perf_event_validate_size() on a partially
+initialized event where event->ctx is NULL, and so when
+for_each_sibling_event() attempts to check event->ctx->mutex, we get a
+splat, as reported by Lucas De Marchi:
+
+ WARNING: CPU: 8 PID: 1471 at kernel/events/core.c:1950 __do_sys_perf_event_open+0xf37/0x1080
+
+This only happens for a new event which is its own group_leader, and in
+this case there cannot be any sibling events. Thus it's safe to skip the
+check for siblings, which avoids having to make invasive and ugly
+changes to for_each_sibling_event().
+
+Avoid the splat by bailing out early when the new event is its own
+group_leader.
+
+Fixes: 382c27f4ed28f803 ("perf: Fix perf_event_validate_size()")
+Closes: https://lore.kernel.org/lkml/20231214000620.3081018-1-lucas.demarchi@intel.com/
+Closes: https://lore.kernel.org/lkml/ZXpm6gQ%2Fd59jGsuW@xpf.sh.intel.com/
+Reported-by: Lucas De Marchi <lucas.demarchi@intel.com>
+Reported-by: Pengfei Xu <pengfei.xu@intel.com>
+Signed-off-by: Mark Rutland <mark.rutland@arm.com>
+Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
+Link: https://lkml.kernel.org/r/20231215112450.3972309-1-mark.rutland@arm.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ kernel/events/core.c | 10 ++++++++++
+ 1 file changed, 10 insertions(+)
+
+--- a/kernel/events/core.c
++++ b/kernel/events/core.c
+@@ -1834,6 +1834,16 @@ static bool perf_event_validate_size(str
+ group_leader->nr_siblings + 1) > 16*1024)
+ return false;
+
++ /*
++ * When creating a new group leader, group_leader->ctx is initialized
++ * after the size has been validated, but we cannot safely use
++ * for_each_sibling_event() until group_leader->ctx is set. A new group
++ * leader cannot have any siblings yet, so we can safely skip checking
++ * the non-existent siblings.
++ */
++ if (event == group_leader)
++ return true;
++
+ for_each_sibling_event(sibling, group_leader) {
+ if (__perf_event_read_size(sibling->attr.read_format,
+ group_leader->nr_siblings + 1) > 16*1024)
projects / thirdparty / kernel / stable-queue.git / commitdiff
