December 2024 - Linux-stable-mirror

FAILED: patch "[PATCH] btrfs: allow swap activation to be interruptible" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 9a45022a0efadd99bcc58f7f1cc2b6fb3b808c40 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024123037-theology-zookeeper-1b67@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 9a45022a0efadd99bcc58f7f1cc2b6fb3b808c40 Mon Sep 17 00:00:00 2001 From: Filipe Manana <fdmanana(a)suse.com> Date: Mon, 9 Dec 2024 16:31:41 +0000 Subject: [PATCH] btrfs: allow swap activation to be interruptible During swap activation we iterate over the extents of a file, then do several checks for each extent, some of which may take some significant time such as checking if an extent is shared. Since a file can have many thousands of extents, this can be a very slow operation and it's currently not interruptible. I had a bug during development of a previous patch that resulted in an infinite loop when iterating the extents, so a core was busy looping and I couldn't cancel the operation, which is very annoying and requires a reboot. So make the loop interruptible by checking for fatal signals at the end of each iteration and stopping immediately if there is one. CC: stable(a)vger.kernel.org # 5.4+ Reviewed-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index b87f19630b00..c4675f4345fd 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -10073,6 +10073,11 @@ static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file, bsi.block_start = physical_block_start; bsi.block_len = len; } + + if (fatal_signal_pending(current)) { + ret = -EINTR; + goto out; + } } if (bsi.block_len)

1 week, 2 days

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FAILED: patch "[PATCH] btrfs: allow swap activation to be interruptible" failed to apply to 6.12-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x 9a45022a0efadd99bcc58f7f1cc2b6fb3b808c40 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024123036-grout-exposure-3af8@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 9a45022a0efadd99bcc58f7f1cc2b6fb3b808c40 Mon Sep 17 00:00:00 2001 From: Filipe Manana <fdmanana(a)suse.com> Date: Mon, 9 Dec 2024 16:31:41 +0000 Subject: [PATCH] btrfs: allow swap activation to be interruptible During swap activation we iterate over the extents of a file, then do several checks for each extent, some of which may take some significant time such as checking if an extent is shared. Since a file can have many thousands of extents, this can be a very slow operation and it's currently not interruptible. I had a bug during development of a previous patch that resulted in an infinite loop when iterating the extents, so a core was busy looping and I couldn't cancel the operation, which is very annoying and requires a reboot. So make the loop interruptible by checking for fatal signals at the end of each iteration and stopping immediately if there is one. CC: stable(a)vger.kernel.org # 5.4+ Reviewed-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index b87f19630b00..c4675f4345fd 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -10073,6 +10073,11 @@ static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file, bsi.block_start = physical_block_start; bsi.block_len = len; } + + if (fatal_signal_pending(current)) { + ret = -EINTR; + goto out; + } } if (bsi.block_len)

1 week, 2 days

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FAILED: patch "[PATCH] btrfs: fix use-after-free waiting for encoded read endios" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x d29662695ed7c015521e5fc9387df25aab192a2e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024123056-thrash-utility-f7d7@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From d29662695ed7c015521e5fc9387df25aab192a2e Mon Sep 17 00:00:00 2001 From: Johannes Thumshirn <johannes.thumshirn(a)wdc.com> Date: Wed, 13 Nov 2024 18:16:49 +0100 Subject: [PATCH] btrfs: fix use-after-free waiting for encoded read endios Fix a use-after-free in the I/O completion path for encoded reads by using a completion instead of a wait_queue for synchronizing the destruction of 'struct btrfs_encoded_read_private'. Fixes: 1881fba89bd5 ("btrfs: add BTRFS_IOC_ENCODED_READ ioctl") CC: stable(a)vger.kernel.org # 6.1+ Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Reviewed-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn(a)wdc.com> Reviewed-by: David Sterba <dsterba(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 94c8809e8170..6baa0269a85b 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -9078,9 +9078,9 @@ static ssize_t btrfs_encoded_read_inline( } struct btrfs_encoded_read_private { - wait_queue_head_t wait; + struct completion done; void *uring_ctx; - atomic_t pending; + refcount_t pending_refs; blk_status_t status; }; @@ -9099,14 +9099,14 @@ static void btrfs_encoded_read_endio(struct btrfs_bio *bbio) */ WRITE_ONCE(priv->status, bbio->bio.bi_status); } - if (atomic_dec_and_test(&priv->pending)) { + if (refcount_dec_and_test(&priv->pending_refs)) { int err = blk_status_to_errno(READ_ONCE(priv->status)); if (priv->uring_ctx) { btrfs_uring_read_extent_endio(priv->uring_ctx, err); kfree(priv); } else { - wake_up(&priv->wait); + complete(&priv->done); } } bio_put(&bbio->bio); @@ -9126,8 +9126,8 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, if (!priv) return -ENOMEM; - init_waitqueue_head(&priv->wait); - atomic_set(&priv->pending, 1); + init_completion(&priv->done); + refcount_set(&priv->pending_refs, 1); priv->status = 0; priv->uring_ctx = uring_ctx; @@ -9140,7 +9140,7 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, size_t bytes = min_t(u64, disk_io_size, PAGE_SIZE); if (bio_add_page(&bbio->bio, pages[i], bytes, 0) < bytes) { - atomic_inc(&priv->pending); + refcount_inc(&priv->pending_refs); btrfs_submit_bbio(bbio, 0); bbio = btrfs_bio_alloc(BIO_MAX_VECS, REQ_OP_READ, fs_info, @@ -9155,11 +9155,11 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, disk_io_size -= bytes; } while (disk_io_size); - atomic_inc(&priv->pending); + refcount_inc(&priv->pending_refs); btrfs_submit_bbio(bbio, 0); if (uring_ctx) { - if (atomic_dec_return(&priv->pending) == 0) { + if (refcount_dec_and_test(&priv->pending_refs)) { ret = blk_status_to_errno(READ_ONCE(priv->status)); btrfs_uring_read_extent_endio(uring_ctx, ret); kfree(priv); @@ -9168,8 +9168,8 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, return -EIOCBQUEUED; } else { - if (atomic_dec_return(&priv->pending) != 0) - io_wait_event(priv->wait, !atomic_read(&priv->pending)); + if (!refcount_dec_and_test(&priv->pending_refs)) + wait_for_completion_io(&priv->done); /* See btrfs_encoded_read_endio() for ordering. */ ret = blk_status_to_errno(READ_ONCE(priv->status)); kfree(priv);

1 week, 2 days

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FAILED: patch "[PATCH] btrfs: fix use-after-free waiting for encoded read endios" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x d29662695ed7c015521e5fc9387df25aab192a2e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024123055-unholy-vice-e16b@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From d29662695ed7c015521e5fc9387df25aab192a2e Mon Sep 17 00:00:00 2001 From: Johannes Thumshirn <johannes.thumshirn(a)wdc.com> Date: Wed, 13 Nov 2024 18:16:49 +0100 Subject: [PATCH] btrfs: fix use-after-free waiting for encoded read endios Fix a use-after-free in the I/O completion path for encoded reads by using a completion instead of a wait_queue for synchronizing the destruction of 'struct btrfs_encoded_read_private'. Fixes: 1881fba89bd5 ("btrfs: add BTRFS_IOC_ENCODED_READ ioctl") CC: stable(a)vger.kernel.org # 6.1+ Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Reviewed-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn(a)wdc.com> Reviewed-by: David Sterba <dsterba(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 94c8809e8170..6baa0269a85b 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -9078,9 +9078,9 @@ static ssize_t btrfs_encoded_read_inline( } struct btrfs_encoded_read_private { - wait_queue_head_t wait; + struct completion done; void *uring_ctx; - atomic_t pending; + refcount_t pending_refs; blk_status_t status; }; @@ -9099,14 +9099,14 @@ static void btrfs_encoded_read_endio(struct btrfs_bio *bbio) */ WRITE_ONCE(priv->status, bbio->bio.bi_status); } - if (atomic_dec_and_test(&priv->pending)) { + if (refcount_dec_and_test(&priv->pending_refs)) { int err = blk_status_to_errno(READ_ONCE(priv->status)); if (priv->uring_ctx) { btrfs_uring_read_extent_endio(priv->uring_ctx, err); kfree(priv); } else { - wake_up(&priv->wait); + complete(&priv->done); } } bio_put(&bbio->bio); @@ -9126,8 +9126,8 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, if (!priv) return -ENOMEM; - init_waitqueue_head(&priv->wait); - atomic_set(&priv->pending, 1); + init_completion(&priv->done); + refcount_set(&priv->pending_refs, 1); priv->status = 0; priv->uring_ctx = uring_ctx; @@ -9140,7 +9140,7 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, size_t bytes = min_t(u64, disk_io_size, PAGE_SIZE); if (bio_add_page(&bbio->bio, pages[i], bytes, 0) < bytes) { - atomic_inc(&priv->pending); + refcount_inc(&priv->pending_refs); btrfs_submit_bbio(bbio, 0); bbio = btrfs_bio_alloc(BIO_MAX_VECS, REQ_OP_READ, fs_info, @@ -9155,11 +9155,11 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, disk_io_size -= bytes; } while (disk_io_size); - atomic_inc(&priv->pending); + refcount_inc(&priv->pending_refs); btrfs_submit_bbio(bbio, 0); if (uring_ctx) { - if (atomic_dec_return(&priv->pending) == 0) { + if (refcount_dec_and_test(&priv->pending_refs)) { ret = blk_status_to_errno(READ_ONCE(priv->status)); btrfs_uring_read_extent_endio(uring_ctx, ret); kfree(priv); @@ -9168,8 +9168,8 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, return -EIOCBQUEUED; } else { - if (atomic_dec_return(&priv->pending) != 0) - io_wait_event(priv->wait, !atomic_read(&priv->pending)); + if (!refcount_dec_and_test(&priv->pending_refs)) + wait_for_completion_io(&priv->done); /* See btrfs_encoded_read_endio() for ordering. */ ret = blk_status_to_errno(READ_ONCE(priv->status)); kfree(priv);

1 week, 2 days

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FAILED: patch "[PATCH] btrfs: fix use-after-free waiting for encoded read endios" failed to apply to 6.12-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x d29662695ed7c015521e5fc9387df25aab192a2e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024123053-neurosis-bounding-947c@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From d29662695ed7c015521e5fc9387df25aab192a2e Mon Sep 17 00:00:00 2001 From: Johannes Thumshirn <johannes.thumshirn(a)wdc.com> Date: Wed, 13 Nov 2024 18:16:49 +0100 Subject: [PATCH] btrfs: fix use-after-free waiting for encoded read endios Fix a use-after-free in the I/O completion path for encoded reads by using a completion instead of a wait_queue for synchronizing the destruction of 'struct btrfs_encoded_read_private'. Fixes: 1881fba89bd5 ("btrfs: add BTRFS_IOC_ENCODED_READ ioctl") CC: stable(a)vger.kernel.org # 6.1+ Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Reviewed-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn(a)wdc.com> Reviewed-by: David Sterba <dsterba(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 94c8809e8170..6baa0269a85b 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -9078,9 +9078,9 @@ static ssize_t btrfs_encoded_read_inline( } struct btrfs_encoded_read_private { - wait_queue_head_t wait; + struct completion done; void *uring_ctx; - atomic_t pending; + refcount_t pending_refs; blk_status_t status; }; @@ -9099,14 +9099,14 @@ static void btrfs_encoded_read_endio(struct btrfs_bio *bbio) */ WRITE_ONCE(priv->status, bbio->bio.bi_status); } - if (atomic_dec_and_test(&priv->pending)) { + if (refcount_dec_and_test(&priv->pending_refs)) { int err = blk_status_to_errno(READ_ONCE(priv->status)); if (priv->uring_ctx) { btrfs_uring_read_extent_endio(priv->uring_ctx, err); kfree(priv); } else { - wake_up(&priv->wait); + complete(&priv->done); } } bio_put(&bbio->bio); @@ -9126,8 +9126,8 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, if (!priv) return -ENOMEM; - init_waitqueue_head(&priv->wait); - atomic_set(&priv->pending, 1); + init_completion(&priv->done); + refcount_set(&priv->pending_refs, 1); priv->status = 0; priv->uring_ctx = uring_ctx; @@ -9140,7 +9140,7 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, size_t bytes = min_t(u64, disk_io_size, PAGE_SIZE); if (bio_add_page(&bbio->bio, pages[i], bytes, 0) < bytes) { - atomic_inc(&priv->pending); + refcount_inc(&priv->pending_refs); btrfs_submit_bbio(bbio, 0); bbio = btrfs_bio_alloc(BIO_MAX_VECS, REQ_OP_READ, fs_info, @@ -9155,11 +9155,11 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, disk_io_size -= bytes; } while (disk_io_size); - atomic_inc(&priv->pending); + refcount_inc(&priv->pending_refs); btrfs_submit_bbio(bbio, 0); if (uring_ctx) { - if (atomic_dec_return(&priv->pending) == 0) { + if (refcount_dec_and_test(&priv->pending_refs)) { ret = blk_status_to_errno(READ_ONCE(priv->status)); btrfs_uring_read_extent_endio(uring_ctx, ret); kfree(priv); @@ -9168,8 +9168,8 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, return -EIOCBQUEUED; } else { - if (atomic_dec_return(&priv->pending) != 0) - io_wait_event(priv->wait, !atomic_read(&priv->pending)); + if (!refcount_dec_and_test(&priv->pending_refs)) + wait_for_completion_io(&priv->done); /* See btrfs_encoded_read_endio() for ordering. */ ret = blk_status_to_errno(READ_ONCE(priv->status)); kfree(priv);

1 week, 2 days

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FAILED: patch "[PATCH] btrfs: check folio mapping after unlock in" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 3e74859ee35edc33a022c3f3971df066ea0ca6b9 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024123045-parka-sublet-a95d@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 3e74859ee35edc33a022c3f3971df066ea0ca6b9 Mon Sep 17 00:00:00 2001 From: Boris Burkov <boris(a)bur.io> Date: Fri, 13 Dec 2024 12:22:32 -0800 Subject: [PATCH] btrfs: check folio mapping after unlock in relocate_one_folio() When we call btrfs_read_folio() to bring a folio uptodate, we unlock the folio. The result of that is that a different thread can modify the mapping (like remove it with invalidate) before we call folio_lock(). This results in an invalid page and we need to try again. In particular, if we are relocating concurrently with aborting a transaction, this can result in a crash like the following: BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] SMP CPU: 76 PID: 1411631 Comm: kworker/u322:5 Workqueue: events_unbound btrfs_reclaim_bgs_work RIP: 0010:set_page_extent_mapped+0x20/0xb0 RSP: 0018:ffffc900516a7be8 EFLAGS: 00010246 RAX: ffffea009e851d08 RBX: ffffea009e0b1880 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffc900516a7b90 RDI: ffffea009e0b1880 RBP: 0000000003573000 R08: 0000000000000001 R09: ffff88c07fd2f3f0 R10: 0000000000000000 R11: 0000194754b575be R12: 0000000003572000 R13: 0000000003572fff R14: 0000000000100cca R15: 0000000005582fff FS: 0000000000000000(0000) GS:ffff88c07fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000407d00f002 CR4: 00000000007706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> ? __die+0x78/0xc0 ? page_fault_oops+0x2a8/0x3a0 ? __switch_to+0x133/0x530 ? wq_worker_running+0xa/0x40 ? exc_page_fault+0x63/0x130 ? asm_exc_page_fault+0x22/0x30 ? set_page_extent_mapped+0x20/0xb0 relocate_file_extent_cluster+0x1a7/0x940 relocate_data_extent+0xaf/0x120 relocate_block_group+0x20f/0x480 btrfs_relocate_block_group+0x152/0x320 btrfs_relocate_chunk+0x3d/0x120 btrfs_reclaim_bgs_work+0x2ae/0x4e0 process_scheduled_works+0x184/0x370 worker_thread+0xc6/0x3e0 ? blk_add_timer+0xb0/0xb0 kthread+0xae/0xe0 ? flush_tlb_kernel_range+0x90/0x90 ret_from_fork+0x2f/0x40 ? flush_tlb_kernel_range+0x90/0x90 ret_from_fork_asm+0x11/0x20 </TASK> This occurs because cleanup_one_transaction() calls destroy_delalloc_inodes() which calls invalidate_inode_pages2() which takes the folio_lock before setting mapping to NULL. We fail to check this, and subsequently call set_extent_mapping(), which assumes that mapping != NULL (in fact it asserts that in debug mode) Note that the "fixes" patch here is not the one that introduced the race (the very first iteration of this code from 2009) but a more recent change that made this particular crash happen in practice. Fixes: e7f1326cc24e ("btrfs: set page extent mapped after read_folio in relocate_one_page") CC: stable(a)vger.kernel.org # 6.1+ Reviewed-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: Boris Burkov <boris(a)bur.io> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index bf267bdfa8f8..db8b42f674b7 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -2902,6 +2902,7 @@ static int relocate_one_folio(struct reloc_control *rc, const bool use_rst = btrfs_need_stripe_tree_update(fs_info, rc->block_group->flags); ASSERT(index <= last_index); +again: folio = filemap_lock_folio(inode->i_mapping, index); if (IS_ERR(folio)) { @@ -2937,6 +2938,11 @@ static int relocate_one_folio(struct reloc_control *rc, ret = -EIO; goto release_folio; } + if (folio->mapping != inode->i_mapping) { + folio_unlock(folio); + folio_put(folio); + goto again; + } } /*

1 week, 2 days

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FAILED: patch "[PATCH] btrfs: check folio mapping after unlock in" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 3e74859ee35edc33a022c3f3971df066ea0ca6b9 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024123042-limelight-doily-8703@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 3e74859ee35edc33a022c3f3971df066ea0ca6b9 Mon Sep 17 00:00:00 2001 From: Boris Burkov <boris(a)bur.io> Date: Fri, 13 Dec 2024 12:22:32 -0800 Subject: [PATCH] btrfs: check folio mapping after unlock in relocate_one_folio() When we call btrfs_read_folio() to bring a folio uptodate, we unlock the folio. The result of that is that a different thread can modify the mapping (like remove it with invalidate) before we call folio_lock(). This results in an invalid page and we need to try again. In particular, if we are relocating concurrently with aborting a transaction, this can result in a crash like the following: BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] SMP CPU: 76 PID: 1411631 Comm: kworker/u322:5 Workqueue: events_unbound btrfs_reclaim_bgs_work RIP: 0010:set_page_extent_mapped+0x20/0xb0 RSP: 0018:ffffc900516a7be8 EFLAGS: 00010246 RAX: ffffea009e851d08 RBX: ffffea009e0b1880 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffc900516a7b90 RDI: ffffea009e0b1880 RBP: 0000000003573000 R08: 0000000000000001 R09: ffff88c07fd2f3f0 R10: 0000000000000000 R11: 0000194754b575be R12: 0000000003572000 R13: 0000000003572fff R14: 0000000000100cca R15: 0000000005582fff FS: 0000000000000000(0000) GS:ffff88c07fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000407d00f002 CR4: 00000000007706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> ? __die+0x78/0xc0 ? page_fault_oops+0x2a8/0x3a0 ? __switch_to+0x133/0x530 ? wq_worker_running+0xa/0x40 ? exc_page_fault+0x63/0x130 ? asm_exc_page_fault+0x22/0x30 ? set_page_extent_mapped+0x20/0xb0 relocate_file_extent_cluster+0x1a7/0x940 relocate_data_extent+0xaf/0x120 relocate_block_group+0x20f/0x480 btrfs_relocate_block_group+0x152/0x320 btrfs_relocate_chunk+0x3d/0x120 btrfs_reclaim_bgs_work+0x2ae/0x4e0 process_scheduled_works+0x184/0x370 worker_thread+0xc6/0x3e0 ? blk_add_timer+0xb0/0xb0 kthread+0xae/0xe0 ? flush_tlb_kernel_range+0x90/0x90 ret_from_fork+0x2f/0x40 ? flush_tlb_kernel_range+0x90/0x90 ret_from_fork_asm+0x11/0x20 </TASK> This occurs because cleanup_one_transaction() calls destroy_delalloc_inodes() which calls invalidate_inode_pages2() which takes the folio_lock before setting mapping to NULL. We fail to check this, and subsequently call set_extent_mapping(), which assumes that mapping != NULL (in fact it asserts that in debug mode) Note that the "fixes" patch here is not the one that introduced the race (the very first iteration of this code from 2009) but a more recent change that made this particular crash happen in practice. Fixes: e7f1326cc24e ("btrfs: set page extent mapped after read_folio in relocate_one_page") CC: stable(a)vger.kernel.org # 6.1+ Reviewed-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: Boris Burkov <boris(a)bur.io> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index bf267bdfa8f8..db8b42f674b7 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -2902,6 +2902,7 @@ static int relocate_one_folio(struct reloc_control *rc, const bool use_rst = btrfs_need_stripe_tree_update(fs_info, rc->block_group->flags); ASSERT(index <= last_index); +again: folio = filemap_lock_folio(inode->i_mapping, index); if (IS_ERR(folio)) { @@ -2937,6 +2938,11 @@ static int relocate_one_folio(struct reloc_control *rc, ret = -EIO; goto release_folio; } + if (folio->mapping != inode->i_mapping) { + folio_unlock(folio); + folio_put(folio); + goto again; + } } /*

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FAILED: patch "[PATCH] btrfs: fix use-after-free when COWing tree bock and tracing" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 44f52bbe96dfdbe4aca3818a2534520082a07040 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024123027-yeah-suitcase-41e7@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 44f52bbe96dfdbe4aca3818a2534520082a07040 Mon Sep 17 00:00:00 2001 From: Filipe Manana <fdmanana(a)suse.com> Date: Wed, 11 Dec 2024 16:08:07 +0000 Subject: [PATCH] btrfs: fix use-after-free when COWing tree bock and tracing is enabled When a COWing a tree block, at btrfs_cow_block(), and we have the tracepoint trace_btrfs_cow_block() enabled and preemption is also enabled (CONFIG_PREEMPT=y), we can trigger a use-after-free in the COWed extent buffer while inside the tracepoint code. This is because in some paths that call btrfs_cow_block(), such as btrfs_search_slot(), we are holding the last reference on the extent buffer @buf so btrfs_force_cow_block() drops the last reference on the @buf extent buffer when it calls free_extent_buffer_stale(buf), which schedules the release of the extent buffer with RCU. This means that if we are on a kernel with preemption, the current task may be preempted before calling trace_btrfs_cow_block() and the extent buffer already released by the time trace_btrfs_cow_block() is called, resulting in a use-after-free. Fix this by moving the trace_btrfs_cow_block() from btrfs_cow_block() to btrfs_force_cow_block() before the COWed extent buffer is freed. This also has a side effect of invoking the tracepoint in the tree defrag code, at defrag.c:btrfs_realloc_node(), since btrfs_force_cow_block() is called there, but this is fine and it was actually missing there. Reported-by: syzbot+8517da8635307182c8a5(a)syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/6759a9b9.050a0220.1ac542.000d.GAE@googl… CC: stable(a)vger.kernel.org # 5.4+ Reviewed-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 693dc27ffb89..185985a337b3 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -654,6 +654,8 @@ int btrfs_force_cow_block(struct btrfs_trans_handle *trans, goto error_unlock_cow; } } + + trace_btrfs_cow_block(root, buf, cow); if (unlock_orig) btrfs_tree_unlock(buf); free_extent_buffer_stale(buf); @@ -710,7 +712,6 @@ int btrfs_cow_block(struct btrfs_trans_handle *trans, { struct btrfs_fs_info *fs_info = root->fs_info; u64 search_start; - int ret; if (unlikely(test_bit(BTRFS_ROOT_DELETING, &root->state))) { btrfs_abort_transaction(trans, -EUCLEAN); @@ -751,12 +752,8 @@ int btrfs_cow_block(struct btrfs_trans_handle *trans, * Also We don't care about the error, as it's handled internally. */ btrfs_qgroup_trace_subtree_after_cow(trans, root, buf); - ret = btrfs_force_cow_block(trans, root, buf, parent, parent_slot, - cow_ret, search_start, 0, nest); - - trace_btrfs_cow_block(root, buf, *cow_ret); - - return ret; + return btrfs_force_cow_block(trans, root, buf, parent, parent_slot, + cow_ret, search_start, 0, nest); } ALLOW_ERROR_INJECTION(btrfs_cow_block, ERRNO);

1 week, 2 days

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FAILED: patch "[PATCH] btrfs: fix use-after-free when COWing tree bock and tracing" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 44f52bbe96dfdbe4aca3818a2534520082a07040 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024123025-animal-itunes-c557@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 44f52bbe96dfdbe4aca3818a2534520082a07040 Mon Sep 17 00:00:00 2001 From: Filipe Manana <fdmanana(a)suse.com> Date: Wed, 11 Dec 2024 16:08:07 +0000 Subject: [PATCH] btrfs: fix use-after-free when COWing tree bock and tracing is enabled When a COWing a tree block, at btrfs_cow_block(), and we have the tracepoint trace_btrfs_cow_block() enabled and preemption is also enabled (CONFIG_PREEMPT=y), we can trigger a use-after-free in the COWed extent buffer while inside the tracepoint code. This is because in some paths that call btrfs_cow_block(), such as btrfs_search_slot(), we are holding the last reference on the extent buffer @buf so btrfs_force_cow_block() drops the last reference on the @buf extent buffer when it calls free_extent_buffer_stale(buf), which schedules the release of the extent buffer with RCU. This means that if we are on a kernel with preemption, the current task may be preempted before calling trace_btrfs_cow_block() and the extent buffer already released by the time trace_btrfs_cow_block() is called, resulting in a use-after-free. Fix this by moving the trace_btrfs_cow_block() from btrfs_cow_block() to btrfs_force_cow_block() before the COWed extent buffer is freed. This also has a side effect of invoking the tracepoint in the tree defrag code, at defrag.c:btrfs_realloc_node(), since btrfs_force_cow_block() is called there, but this is fine and it was actually missing there. Reported-by: syzbot+8517da8635307182c8a5(a)syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/6759a9b9.050a0220.1ac542.000d.GAE@googl… CC: stable(a)vger.kernel.org # 5.4+ Reviewed-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 693dc27ffb89..185985a337b3 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -654,6 +654,8 @@ int btrfs_force_cow_block(struct btrfs_trans_handle *trans, goto error_unlock_cow; } } + + trace_btrfs_cow_block(root, buf, cow); if (unlock_orig) btrfs_tree_unlock(buf); free_extent_buffer_stale(buf); @@ -710,7 +712,6 @@ int btrfs_cow_block(struct btrfs_trans_handle *trans, { struct btrfs_fs_info *fs_info = root->fs_info; u64 search_start; - int ret; if (unlikely(test_bit(BTRFS_ROOT_DELETING, &root->state))) { btrfs_abort_transaction(trans, -EUCLEAN); @@ -751,12 +752,8 @@ int btrfs_cow_block(struct btrfs_trans_handle *trans, * Also We don't care about the error, as it's handled internally. */ btrfs_qgroup_trace_subtree_after_cow(trans, root, buf); - ret = btrfs_force_cow_block(trans, root, buf, parent, parent_slot, - cow_ret, search_start, 0, nest); - - trace_btrfs_cow_block(root, buf, *cow_ret); - - return ret; + return btrfs_force_cow_block(trans, root, buf, parent, parent_slot, + cow_ret, search_start, 0, nest); } ALLOW_ERROR_INJECTION(btrfs_cow_block, ERRNO);

1 week, 2 days

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FAILED: patch "[PATCH] btrfs: fix use-after-free when COWing tree bock and tracing" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 44f52bbe96dfdbe4aca3818a2534520082a07040 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024123023-hardy-ravioli-a818@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 44f52bbe96dfdbe4aca3818a2534520082a07040 Mon Sep 17 00:00:00 2001 From: Filipe Manana <fdmanana(a)suse.com> Date: Wed, 11 Dec 2024 16:08:07 +0000 Subject: [PATCH] btrfs: fix use-after-free when COWing tree bock and tracing is enabled When a COWing a tree block, at btrfs_cow_block(), and we have the tracepoint trace_btrfs_cow_block() enabled and preemption is also enabled (CONFIG_PREEMPT=y), we can trigger a use-after-free in the COWed extent buffer while inside the tracepoint code. This is because in some paths that call btrfs_cow_block(), such as btrfs_search_slot(), we are holding the last reference on the extent buffer @buf so btrfs_force_cow_block() drops the last reference on the @buf extent buffer when it calls free_extent_buffer_stale(buf), which schedules the release of the extent buffer with RCU. This means that if we are on a kernel with preemption, the current task may be preempted before calling trace_btrfs_cow_block() and the extent buffer already released by the time trace_btrfs_cow_block() is called, resulting in a use-after-free. Fix this by moving the trace_btrfs_cow_block() from btrfs_cow_block() to btrfs_force_cow_block() before the COWed extent buffer is freed. This also has a side effect of invoking the tracepoint in the tree defrag code, at defrag.c:btrfs_realloc_node(), since btrfs_force_cow_block() is called there, but this is fine and it was actually missing there. Reported-by: syzbot+8517da8635307182c8a5(a)syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/6759a9b9.050a0220.1ac542.000d.GAE@googl… CC: stable(a)vger.kernel.org # 5.4+ Reviewed-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 693dc27ffb89..185985a337b3 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -654,6 +654,8 @@ int btrfs_force_cow_block(struct btrfs_trans_handle *trans, goto error_unlock_cow; } } + + trace_btrfs_cow_block(root, buf, cow); if (unlock_orig) btrfs_tree_unlock(buf); free_extent_buffer_stale(buf); @@ -710,7 +712,6 @@ int btrfs_cow_block(struct btrfs_trans_handle *trans, { struct btrfs_fs_info *fs_info = root->fs_info; u64 search_start; - int ret; if (unlikely(test_bit(BTRFS_ROOT_DELETING, &root->state))) { btrfs_abort_transaction(trans, -EUCLEAN); @@ -751,12 +752,8 @@ int btrfs_cow_block(struct btrfs_trans_handle *trans, * Also We don't care about the error, as it's handled internally. */ btrfs_qgroup_trace_subtree_after_cow(trans, root, buf); - ret = btrfs_force_cow_block(trans, root, buf, parent, parent_slot, - cow_ret, search_start, 0, nest); - - trace_btrfs_cow_block(root, buf, *cow_ret); - - return ret; + return btrfs_force_cow_block(trans, root, buf, parent, parent_slot, + cow_ret, search_start, 0, nest); } ALLOW_ERROR_INJECTION(btrfs_cow_block, ERRNO);

1 week, 2 days

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