December 2024 - Linux-stable-mirror

[PATCH v2] btrfs: do proper folio cleanup when cow_file_range() failed

by Qu Wenruo

[BUG] When testing with COW fixup marked as BUG_ON() (this is involved with the new pin_user_pages*() change, which should not result new out-of-band dirty pages), I hit a crash triggered by the BUG_ON() from hitting COW fixup path. This BUG_ON() happens just after a failed btrfs_run_delalloc_range(): BTRFS error (device dm-2): failed to run delalloc range, root 348 ino 405 folio 65536 submit_bitmap 6-15 start 90112 len 106496: -28 ------------[ cut here ]------------ kernel BUG at fs/btrfs/extent_io.c:1444! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP CPU: 0 UID: 0 PID: 434621 Comm: kworker/u24:8 Tainted: G OE 6.12.0-rc7-custom+ #86 Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022 Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] pc : extent_writepage_io+0x2d4/0x308 [btrfs] lr : extent_writepage_io+0x2d4/0x308 [btrfs] Call trace: extent_writepage_io+0x2d4/0x308 [btrfs] extent_writepage+0x218/0x330 [btrfs] extent_write_cache_pages+0x1d4/0x4b0 [btrfs] btrfs_writepages+0x94/0x150 [btrfs] do_writepages+0x74/0x190 filemap_fdatawrite_wbc+0x88/0xc8 start_delalloc_inodes+0x180/0x3b0 [btrfs] btrfs_start_delalloc_roots+0x174/0x280 [btrfs] shrink_delalloc+0x114/0x280 [btrfs] flush_space+0x250/0x2f8 [btrfs] btrfs_async_reclaim_data_space+0x180/0x228 [btrfs] process_one_work+0x164/0x408 worker_thread+0x25c/0x388 kthread+0x100/0x118 ret_from_fork+0x10/0x20 Code: aa1403e1 9402f3ef aa1403e0 9402f36f (d4210000) ---[ end trace 0000000000000000 ]--- [CAUSE] That failure is mostly from cow_file_range(), where we can hit -ENOSPC. Although the -ENOSPC is already a bug related to our space reservation code, let's just focus on the error handling. For example, we have the following dirty range [0, 64K) of an inode, with 4K sector size and 4K page size: 0 16K 32K 48K 64K |///////////////////////////////////////| |#######################################| Where |///| means page are still dirty, and |###| means the extent io tree has EXTENT_DELALLOC flag. - Enter extent_writepage() for page 0 - Enter btrfs_run_delalloc_range() for range [0, 64K) - Enter cow_file_range() for range [0, 64K) - Function btrfs_reserve_extent() only reserved one 16K extent So we created extent map and ordered extent for range [0, 16K) 0 16K 32K 48K 64K |////////|//////////////////////////////| |<- OE ->|##############################| And range [0, 16K) has its delalloc flag cleared. But since we haven't yet submit any bio, involved 4 pages are still dirty. - Function btrfs_reserve_extent() return with -ENOSPC Now we have to run error cleanup, which will clear all EXTENT_DELALLOC* flags and clear the dirty flags for the remaining ranges: 0 16K 32K 48K 64K |////////| | | | | Note that range [0, 16K) still has their pages dirty. - Some time later, writeback are triggered again for the range [0, 16K) since the page range still have dirty flags. - btrfs_run_delalloc_range() will do nothing because there is no EXTENT_DELALLOC flag. - extent_writepage_io() find page 0 has no ordered flag Which falls into the COW fixup path, triggering the BUG_ON(). Unfortunately this error handling bug dates back to the introduction of btrfs. Thankfully with the abuse of cow fixup, at least it won't crash the kernel. [FIX] Instead of immediately unlock the extent and folios, we keep the extent and folios locked until either erroring out or the whole delalloc range finished. When the whole delalloc range finished without error, we just unlock the whole range with PAGE_SET_ORDERED (and PAGE_UNLOCK for !keep_locked cases), with EXTENT_DELALLOC and EXTENT_LOCKED cleared. And those involved folios will be properly submitted, with their dirty flags cleared during submission. For the error path, it will be a little more complex: - The range with ordered extent allocated (range (1)) We only clear the EXTENT_DELALLOC and EXTENT_LOCKED, as the remaining flags are cleaned up by btrfs_mark_ordered_io_finished()->btrfs_finish_one_ordered(). For folios we finish the IO (clear dirty, start writeback and immediately finish the writeback) and unlock the folios. - The range with reserved extent but no ordered extent (range(2)) - The range we never touched (range(3)) For both range (2) and range(3) the behavior is not changed. Now even if cow_file_range() failed halfway with some successfully reserved extents/ordered extents, we will keep all folios clean, so there will be no future writeback triggered on them. Cc: stable(a)vger.kernel.org Signed-off-by: Qu Wenruo <wqu(a)suse.com> --- Changelog: v2: - Fix the error handling for range (1) Where the patch is still using the old "0", which will not unlock the extent range. --- fs/btrfs/inode.c | 65 ++++++++++++++++++++++++------------------------ 1 file changed, 32 insertions(+), 33 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 9267861f8ab0..9517fb2df649 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1372,6 +1372,17 @@ static noinline int cow_file_range(struct btrfs_inode *inode, alloc_hint = btrfs_get_extent_allocation_hint(inode, start, num_bytes); + /* + * We're not doing compressed IO, don't unlock the first page + * (which the caller expects to stay locked), don't clear any + * dirty bits and don't set any writeback bits + * + * Do set the Ordered (Private2) bit so we know this page was + * properly setup for writepage. + */ + page_ops = (keep_locked ? 0 : PAGE_UNLOCK); + page_ops |= PAGE_SET_ORDERED; + /* * Relocation relies on the relocated extents to have exactly the same * size as the original extents. Normally writeback for relocation data @@ -1431,6 +1442,10 @@ static noinline int cow_file_range(struct btrfs_inode *inode, file_extent.offset = 0; file_extent.compression = BTRFS_COMPRESS_NONE; + /* + * Locked range will be released either during error clean up or + * after the whole range is finished. + */ lock_extent(&inode->io_tree, start, start + cur_alloc_size - 1, &cached); @@ -1476,21 +1491,6 @@ static noinline int cow_file_range(struct btrfs_inode *inode, btrfs_dec_block_group_reservations(fs_info, ins.objectid); - /* - * We're not doing compressed IO, don't unlock the first page - * (which the caller expects to stay locked), don't clear any - * dirty bits and don't set any writeback bits - * - * Do set the Ordered (Private2) bit so we know this page was - * properly setup for writepage. - */ - page_ops = (keep_locked ? 0 : PAGE_UNLOCK); - page_ops |= PAGE_SET_ORDERED; - - extent_clear_unlock_delalloc(inode, start, start + cur_alloc_size - 1, - locked_folio, &cached, - EXTENT_LOCKED | EXTENT_DELALLOC, - page_ops); if (num_bytes < cur_alloc_size) num_bytes = 0; else @@ -1507,6 +1507,9 @@ static noinline int cow_file_range(struct btrfs_inode *inode, if (ret) goto out_unlock; } + extent_clear_unlock_delalloc(inode, orig_start, end, locked_folio, &cached, + EXTENT_LOCKED | EXTENT_DELALLOC, + page_ops); done: if (done_offset) *done_offset = end; @@ -1527,35 +1530,31 @@ static noinline int cow_file_range(struct btrfs_inode *inode, * We process each region below. */ - clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW | - EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV; - page_ops = PAGE_UNLOCK | PAGE_START_WRITEBACK | PAGE_END_WRITEBACK; - /* * For the range (1). We have already instantiated the ordered extents * for this region. They are cleaned up by * btrfs_cleanup_ordered_extents() in e.g, - * btrfs_run_delalloc_range(). EXTENT_LOCKED | EXTENT_DELALLOC are - * already cleared in the above loop. And, EXTENT_DELALLOC_NEW | - * EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV are handled by the cleanup - * function. + * btrfs_run_delalloc_range(). + * EXTENT_DELALLOC_NEW | EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV + * are also handled by the cleanup function. * - * However, in case of @keep_locked, we still need to unlock the pages - * (except @locked_folio) to ensure all the pages are unlocked. + * So here we only clear EXTENT_LOCKED and EXTENT_DELALLOC flag, + * and finish the writeback of the involved folios, which will be + * never submitted. */ - if (keep_locked && orig_start < start) { + if (orig_start < start) { + clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC; + page_ops = PAGE_UNLOCK | PAGE_START_WRITEBACK | PAGE_END_WRITEBACK; + if (!locked_folio) mapping_set_error(inode->vfs_inode.i_mapping, ret); extent_clear_unlock_delalloc(inode, orig_start, start - 1, - locked_folio, NULL, 0, page_ops); + locked_folio, NULL, clear_bits, page_ops); } - /* - * At this point we're unlocked, we want to make sure we're only - * clearing these flags under the extent lock, so lock the rest of the - * range and clear everything up. - */ - lock_extent(&inode->io_tree, start, end, NULL); + clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW | + EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV; + page_ops = PAGE_UNLOCK | PAGE_START_WRITEBACK | PAGE_END_WRITEBACK; /* * For the range (2). If we reserved an extent for our delalloc range -- 2.47.1

1 month, 3 weeks

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[PATCH] crypto: qce - fix priority to be less than ARMv8 CE

by Eric Biggers

From: Eric Biggers <ebiggers(a)google.com> As QCE is an order of magnitude slower than the ARMv8 Crypto Extensions on the CPU, and is also less well tested, give it a lower priority. Previously the QCE SHA algorithms had higher priority than the ARMv8 CE equivalents, and the ciphers such as AES-XTS had the same priority which meant the QCE versions were chosen if they happened to be loaded later. Fixes: ec8f5d8f6f76 ("crypto: qce - Qualcomm crypto engine driver") Cc: stable(a)vger.kernel.org Cc: Bartosz Golaszewski <brgl(a)bgdev.pl> Cc: Neil Armstrong <neil.armstrong(a)linaro.org> Cc: Thara Gopinath <thara.gopinath(a)gmail.com> Signed-off-by: Eric Biggers <ebiggers(a)google.com> --- drivers/crypto/qce/aead.c | 2 +- drivers/crypto/qce/sha.c | 2 +- drivers/crypto/qce/skcipher.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/crypto/qce/aead.c b/drivers/crypto/qce/aead.c index 7d811728f047..97b56e92ea33 100644 --- a/drivers/crypto/qce/aead.c +++ b/drivers/crypto/qce/aead.c @@ -784,11 +784,11 @@ static int qce_aead_register_one(const struct qce_aead_def *def, struct qce_devi alg->encrypt = qce_aead_encrypt; alg->decrypt = qce_aead_decrypt; alg->init = qce_aead_init; alg->exit = qce_aead_exit; - alg->base.cra_priority = 300; + alg->base.cra_priority = 275; alg->base.cra_flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY | CRYPTO_ALG_KERN_DRIVER_ONLY | CRYPTO_ALG_NEED_FALLBACK; alg->base.cra_ctxsize = sizeof(struct qce_aead_ctx); diff --git a/drivers/crypto/qce/sha.c b/drivers/crypto/qce/sha.c index fc72af8aa9a7..71b748183cfa 100644 --- a/drivers/crypto/qce/sha.c +++ b/drivers/crypto/qce/sha.c @@ -480,11 +480,11 @@ static int qce_ahash_register_one(const struct qce_ahash_def *def, else if (IS_SHA256(def->flags)) tmpl->hash_zero = sha256_zero_message_hash; base = &alg->halg.base; base->cra_blocksize = def->blocksize; - base->cra_priority = 300; + base->cra_priority = 175; base->cra_flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_KERN_DRIVER_ONLY; base->cra_ctxsize = sizeof(struct qce_sha_ctx); base->cra_alignmask = 0; base->cra_module = THIS_MODULE; base->cra_init = qce_ahash_cra_init; diff --git a/drivers/crypto/qce/skcipher.c b/drivers/crypto/qce/skcipher.c index 5b493fdc1e74..ffb334eb5b34 100644 --- a/drivers/crypto/qce/skcipher.c +++ b/drivers/crypto/qce/skcipher.c @@ -459,11 +459,11 @@ static int qce_skcipher_register_one(const struct qce_skcipher_def *def, IS_DES(def->flags) ? qce_des_setkey : qce_skcipher_setkey; alg->encrypt = qce_skcipher_encrypt; alg->decrypt = qce_skcipher_decrypt; - alg->base.cra_priority = 300; + alg->base.cra_priority = 275; alg->base.cra_flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY | CRYPTO_ALG_KERN_DRIVER_ONLY; alg->base.cra_ctxsize = sizeof(struct qce_cipher_ctx); alg->base.cra_alignmask = 0; base-commit: ceb8bf2ceaa77fe222fe8fe32cb7789c9099ddf1 -- 2.47.1

1 month, 3 weeks

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Re: kernel v6.7 warn in add_uevent_var: buffer size too small

by Greg KH

On Wed, Dec 04, 2024 at 05:29:26PM +0800, wzs wrote: > Hello, > when fuzzing the Linux kernel 6.7.0, > the following crash was triggered. > > kernel config : https://pastebin.com/3JeQFdUr > console output : https://pastebin.com/9ADtBQtP > > Basically, we use gadget module to simulate the connection and interaction > process of a USB device > (device type code : 0003, vendor id : 046D, product id : C312, serial > number : 27B4, with function : input event). > > It seems to be caused by a mismatch between the uevent's environmental > limit and the buffer size used to receive the uevent, which triggers such > kernel warning. > > The crash report is as follow: > 、、、 > [203835.102225] input: wingfuz Keyboard as > /devices/platform/dummy_hcd.0/usb3/3-1/3-1:1.0/0003:046D:C312.27B4/input/input5893 > [203835.155527] ------------[ cut here ]------------ > [203835.155533] add_uevent_var: buffer size too small > [203835.162092] WARNING: CPU: 11 PID: 57434 at lib/kobject_uevent.c:671 > add_uevent_var+0x2fe/0x390 I think this is already fixed in newer kernel versions. 6.7.0 is very old and obsolete. Can you test this on 6.12.1? thanks, greg k-h

1 month, 3 weeks

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[PATCH 0/6] rtc: Fix problems with missing UIE irqs

by Esben Haabendal

This fixes a couple of different problems, that can cause RTC (alarm) irqs to be missing when generating UIE interrupts. The first commit fixes a long-standing problem, which has been documented in a comment since 2010. This fixes a race that could cause UIE irqs to stop being generated, which was easily reproduced by timing the use of RTC_UIE_ON ioctl with the seconds tick in the RTC. The last commit ensures that RTC (alarm) irqs are enabled whenever RTC_UIE_ON ioctl is used. The driver specific commits avoids kernel warnings about unbalanced enable_irq/disable_irq, which gets triggered on first RTC_UIE_ON with the last commit. Before this series, the same warning should be seen on initial RTC_AIE_ON with those drivers. Signed-off-by: Esben Haabendal <esben(a)geanix.com> --- Esben Haabendal (6): rtc: interface: Fix long-standing race when setting alarm rtc: isl12022: Fix initial enable_irq/disable_irq balance rtc: cpcap: Fix initial enable_irq/disable_irq balance rtc: st-lpc: Fix initial enable_irq/disable_irq balance rtc: tps6586x: Fix initial enable_irq/disable_irq balance rtc: interface: Ensure alarm irq is enabled when UIE is enabled drivers/rtc/interface.c | 27 +++++++++++++++++++++++++++ drivers/rtc/rtc-cpcap.c | 1 + drivers/rtc/rtc-isl12022.c | 1 + drivers/rtc/rtc-st-lpc.c | 1 + drivers/rtc/rtc-tps6586x.c | 1 + 5 files changed, 31 insertions(+) --- base-commit: 40384c840ea1944d7c5a392e8975ed088ecf0b37 change-id: 20241203-rtc-uie-irq-fixes-f2838782d0f8 Best regards, -- Esben Haabendal <esben(a)geanix.com>

1 month, 3 weeks

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[PATCH v2 5.15] tty: n_gsm: Fix use-after-free in gsm_cleanup_mux

by mingli.yu＠eng.windriver.com

From: Longlong Xia <xialonglong(a)kylinos.cn> commit 9462f4ca56e7d2430fdb6dcc8498244acbfc4489 upstream. BUG: KASAN: slab-use-after-free in gsm_cleanup_mux+0x77b/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm] Read of size 8 at addr ffff88815fe99c00 by task poc/3379 CPU: 0 UID: 0 PID: 3379 Comm: poc Not tainted 6.11.0+ #56 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 Call Trace: <TASK> gsm_cleanup_mux+0x77b/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm] __pfx_gsm_cleanup_mux+0x10/0x10 drivers/tty/n_gsm.c:3124 [n_gsm] __pfx_sched_clock_cpu+0x10/0x10 kernel/sched/clock.c:389 update_load_avg+0x1c1/0x27b0 kernel/sched/fair.c:4500 __pfx_min_vruntime_cb_rotate+0x10/0x10 kernel/sched/fair.c:846 __rb_insert_augmented+0x492/0xbf0 lib/rbtree.c:161 gsmld_ioctl+0x395/0x1450 drivers/tty/n_gsm.c:3408 [n_gsm] _raw_spin_lock_irqsave+0x92/0xf0 arch/x86/include/asm/atomic.h:107 __pfx_gsmld_ioctl+0x10/0x10 drivers/tty/n_gsm.c:3822 [n_gsm] ktime_get+0x5e/0x140 kernel/time/timekeeping.c:195 ldsem_down_read+0x94/0x4e0 arch/x86/include/asm/atomic64_64.h:79 __pfx_ldsem_down_read+0x10/0x10 drivers/tty/tty_ldsem.c:338 __pfx_do_vfs_ioctl+0x10/0x10 fs/ioctl.c:805 tty_ioctl+0x643/0x1100 drivers/tty/tty_io.c:2818 Allocated by task 65: gsm_data_alloc.constprop.0+0x27/0x190 drivers/tty/n_gsm.c:926 [n_gsm] gsm_send+0x2c/0x580 drivers/tty/n_gsm.c:819 [n_gsm] gsm1_receive+0x547/0xad0 drivers/tty/n_gsm.c:3038 [n_gsm] gsmld_receive_buf+0x176/0x280 drivers/tty/n_gsm.c:3609 [n_gsm] tty_ldisc_receive_buf+0x101/0x1e0 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x61/0xa0 drivers/tty/tty_port.c:39 flush_to_ldisc+0x1b0/0x750 drivers/tty/tty_buffer.c:445 process_scheduled_works+0x2b0/0x10d0 kernel/workqueue.c:3229 worker_thread+0x3dc/0x950 kernel/workqueue.c:3391 kthread+0x2a3/0x370 kernel/kthread.c:389 ret_from_fork+0x2d/0x70 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:257 Freed by task 3367: kfree+0x126/0x420 mm/slub.c:4580 gsm_cleanup_mux+0x36c/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm] gsmld_ioctl+0x395/0x1450 drivers/tty/n_gsm.c:3408 [n_gsm] tty_ioctl+0x643/0x1100 drivers/tty/tty_io.c:2818 [Analysis] gsm_msg on the tx_ctrl_list or tx_data_list of gsm_mux can be freed by multi threads through ioctl,which leads to the occurrence of uaf. Protect it by gsm tx lock. Signed-off-by: Longlong Xia <xialonglong(a)kylinos.cn> Cc: stable <stable(a)kernel.org> Suggested-by: Jiri Slaby <jirislaby(a)kernel.org> Link: https://lore.kernel.org/r/20240926130213.531959-1-xialonglong@kylinos.cn Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> [Mingli: Backport to fix CVE-2024-50073, no guard macro defined resolution] Signed-off-by: Mingli Yu <mingli.yu(a)windriver.com> --- drivers/tty/n_gsm.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index aae9f73585bd..1becbdf7c470 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -2443,6 +2443,7 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm, bool disc) int i; struct gsm_dlci *dlci; struct gsm_msg *txq, *ntxq; + unsigned long flags; gsm->dead = true; mutex_lock(&gsm->mutex); @@ -2471,9 +2472,12 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm, bool disc) mutex_unlock(&gsm->mutex); /* Now wipe the queues */ tty_ldisc_flush(gsm->tty); + + spin_lock_irqsave(&gsm->tx_lock, flags); list_for_each_entry_safe(txq, ntxq, &gsm->tx_list, list) kfree(txq); INIT_LIST_HEAD(&gsm->tx_list); + spin_unlock_irqrestore(&gsm->tx_lock, flags); } /** -- 2.34.1

1 month, 3 weeks

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[PATCH net] net :mana :Request a V2 response version for MANA_QUERY_GF_STAT

by Shradha Gupta

The current requested response version(V1) for MANA_QUERY_GF_STAT query results in STATISTICS_FLAGS_TX_ERRORS_GDMA_ERROR value being set to 0 always. In order to get the correct value for this counter we request the response version to be V2. Cc: stable(a)vger.kernel.org Fixes: e1df5202e879 ("net :mana :Add remaining GDMA stats for MANA to ethtool") Signed-off-by: Shradha Gupta <shradhagupta(a)linux.microsoft.com> --- drivers/net/ethernet/microsoft/mana/mana_en.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index 57ac732e7707..f73848a4feb3 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c @@ -2536,6 +2536,7 @@ void mana_query_gf_stats(struct mana_port_context *apc) mana_gd_init_req_hdr(&req.hdr, MANA_QUERY_GF_STAT, sizeof(req), sizeof(resp)); + req.hdr.resp.msg_version = GDMA_MESSAGE_V2; req.req_stats = STATISTICS_FLAGS_RX_DISCARDS_NO_WQE | STATISTICS_FLAGS_RX_ERRORS_VPORT_DISABLED | STATISTICS_FLAGS_HC_RX_BYTES | -- 2.43.0

1 month, 3 weeks

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Re: [PATCH] riscv: Fix vector state restore in rt_sigreturn()

by Yangyu Chen

I think this patch should also be backported to the v6.6 LTS tree. Since it should recolonize as Fixes: 8ee0b41898 ("riscv: signal: Add sigcontext save/restore for vector") and that commit first appears since v6.5-rc1 and this patch land to master branch since v6.9-rc3 Thanks, Yangyu Chen On 4/3/24 15:26, Björn Töpel wrote: > From: Björn Töpel <bjorn(a)rivosinc.com> > The RISC-V Vector specification states in "Appendix D: Calling > Convention for Vector State" [1] that "Executing a system call causes > all caller-saved vector registers (v0-v31, vl, vtype) and vstart to > become unspecified.". In the RISC-V kernel this is called "discarding > the vstate". > Returning from a signal handler via the rt_sigreturn() syscall, vector > discard is also performed. However, this is not an issue since the > vector state should be restored from the sigcontext, and therefore not > care about the vector discard. > The "live state" is the actual vector register in the running context, > and the "vstate" is the vector state of the task. A dirty live state, > means that the vstate and live state are not in synch. > When vectorized user_from_copy() was introduced, an bug sneaked in at > the restoration code, related to the discard of the live state. > An example when this go wrong: > 1. A userland application is executing vector code > 2. The application receives a signal, and the signal handler is > entered. > 3. The application returns from the signal handler, using the > rt_sigreturn() syscall. > 4. The live vector state is discarded upon entering the > rt_sigreturn(), and the live state is marked as "dirty", indicating > that the live state need to be synchronized with the current > vstate. > 5. rt_sigreturn() restores the vstate, except the Vector registers, > from the sigcontext > 6. rt_sigreturn() restores the Vector registers, from the sigcontext, > and now the vectorized user_from_copy() is used. The dirty live > state from the discard is saved to the vstate, making the vstate > corrupt. > 7. rt_sigreturn() returns to the application, which crashes due to > corrupted vstate. > Note that the vectorized user_from_copy() is invoked depending on the > value of CONFIG_RISCV_ISA_V_UCOPY_THRESHOLD. Default is 768, which > means that vlen has to be larger than 128b for this bug to trigger. > The fix is simply to mark the live state as non-dirty/clean prior > performing the vstate restore. > Link: https://github.com/riscv/riscv-isa-manual/releases/download/riscv-isa-relea… # [1] > Reported-by: Charlie Jenkins <charlie(a)rivosinc.com> > Reported-by: Vineet Gupta <vgupta(a)kernel.org> > Fixes: c2a658d41924 ("riscv: lib: vectorize copy_to_user/copy_from_user") > Signed-off-by: Björn Töpel <bjorn(a)rivosinc.com> > --- > arch/riscv/kernel/signal.c | 15 ++++++++------- > 1 file changed, 8 insertions(+), 7 deletions(-) > diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c > index 501e66debf69..5a2edd7f027e 100644 > --- a/arch/riscv/kernel/signal.c > +++ b/arch/riscv/kernel/signal.c > @@ -119,6 +119,13 @@ static long __restore_v_state(struct pt_regs *regs, void __user *sc_vec) > struct __sc_riscv_v_state __user *state = sc_vec; > void __user *datap; > + /* > + * Mark the vstate as clean prior performing the actual copy, > + * to avoid getting the vstate incorrectly clobbered by the > + * discarded vector state. > + */ > + riscv_v_vstate_set_restore(current, regs); > + > /* Copy everything of __sc_riscv_v_state except datap. */ > err = __copy_from_user(&current->thread.vstate, &state->v_state, > offsetof(struct __riscv_v_ext_state, datap)); > @@ -133,13 +140,7 @@ static long __restore_v_state(struct pt_regs *regs, void __user *sc_vec) > * Copy the whole vector content from user space datap. Use > * copy_from_user to prevent information leak. > */ > - err = copy_from_user(current->thread.vstate.datap, datap, riscv_v_vsize); > - if (unlikely(err)) > - return err; > - > - riscv_v_vstate_set_restore(current, regs); > - > - return err; > + return copy_from_user(current->thread.vstate.datap, datap, riscv_v_vsize); > } > #else > #define save_v_state(task, regs) (0) > base-commit: 7115ff4a8bfed3b9294bad2e111744e6abeadf1a

1 month, 3 weeks

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[PATCH net-next v2 0/5] virtio_net: correct netdev_tx_reset_queue() invocation points

by Koichiro Den

When virtnet_close is followed by virtnet_open, some TX completions can possibly remain unconsumed, until they are finally processed during the first NAPI poll after the netdev_tx_reset_queue(), resulting in a crash [1]. Commit b96ed2c97c79 ("virtio_net: move netdev_tx_reset_queue() call before RX napi enable") was not sufficient to eliminate all BQL crash cases for virtio-net. This issue can be reproduced with the latest net-next master by running: `while :; do ip l set DEV down; ip l set DEV up; done` under heavy network TX load from inside the machine. This patch series resolves the issue and also addresses similar existing problems: (a). Drop netdev_tx_reset_queue() from open/close path. This eliminates the BQL crashes due to the problematic open/close path. (b). As a result of (a), netdev_tx_reset_queue() is now explicitly required in freeze/restore path. Add netdev_tx_reset_queue() to free_unused_bufs(). (c). Fix missing resetting in virtnet_tx_resize(). virtnet_tx_resize() has lacked proper resetting since commit c8bd1f7f3e61 ("virtio_net: add support for Byte Queue Limits"). (d). Fix missing resetting in the XDP_SETUP_XSK_POOL path. Similar to (c), this path lacked proper resetting. Call netdev_tx_reset_queue() when virtqueue_reset() has actually recycled unused buffers. This patch series consists of five commits: [1/5]: Resolves (a) and (b). [2/5]: Prerequisite for (c). [3/5]: Resolves (c). [4/5]: Preresuisite for (d). [5/5]: Resolves (d). Changes for v2: - add tx queue resetting for (b) to (d) above v1: https://lore.kernel.org/all/20241130181744.3772632-1-koichiro.den@canonical… [1]: ------------[ cut here ]------------ kernel BUG at lib/dynamic_queue_limits.c:99! Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 7 UID: 0 PID: 1598 Comm: ip Tainted: G N 6.12.0net-next_main+ #2 Tainted: [N]=TEST Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), \ BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:dql_completed+0x26b/0x290 Code: b7 c2 49 89 e9 44 89 da 89 c6 4c 89 d7 e8 ed 17 47 00 58 65 ff 0d 4d 27 90 7e 0f 85 fd fe ff ff e8 ea 53 8d ff e9 f3 fe ff ff <0f> 0b 01 d2 44 89 d1 29 d1 ba 00 00 00 00 0f 48 ca e9 28 ff ff ff RSP: 0018:ffffc900002b0d08 EFLAGS: 00010297 RAX: 0000000000000000 RBX: ffff888102398c80 RCX: 0000000080190009 RDX: 0000000000000000 RSI: 000000000000006a RDI: 0000000000000000 RBP: ffff888102398c00 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000000ca R11: 0000000000015681 R12: 0000000000000001 R13: ffffc900002b0d68 R14: ffff88811115e000 R15: ffff8881107aca40 FS: 00007f41ded69500(0000) GS:ffff888667dc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556ccc2dc1a0 CR3: 0000000104fd8003 CR4: 0000000000772ef0 PKRU: 55555554 Call Trace: <IRQ> ? die+0x32/0x80 ? do_trap+0xd9/0x100 ? dql_completed+0x26b/0x290 ? dql_completed+0x26b/0x290 ? do_error_trap+0x6d/0xb0 ? dql_completed+0x26b/0x290 ? exc_invalid_op+0x4c/0x60 ? dql_completed+0x26b/0x290 ? asm_exc_invalid_op+0x16/0x20 ? dql_completed+0x26b/0x290 __free_old_xmit+0xff/0x170 [virtio_net] free_old_xmit+0x54/0xc0 [virtio_net] virtnet_poll+0xf4/0xe30 [virtio_net] ? __update_load_avg_cfs_rq+0x264/0x2d0 ? update_curr+0x35/0x260 ? reweight_entity+0x1be/0x260 __napi_poll.constprop.0+0x28/0x1c0 net_rx_action+0x329/0x420 ? enqueue_hrtimer+0x35/0x90 ? trace_hardirqs_on+0x1d/0x80 ? kvm_sched_clock_read+0xd/0x20 ? sched_clock+0xc/0x30 ? kvm_sched_clock_read+0xd/0x20 ? sched_clock+0xc/0x30 ? sched_clock_cpu+0xd/0x1a0 handle_softirqs+0x138/0x3e0 do_softirq.part.0+0x89/0xc0 </IRQ> <TASK> __local_bh_enable_ip+0xa7/0xb0 virtnet_open+0xc8/0x310 [virtio_net] __dev_open+0xfa/0x1b0 __dev_change_flags+0x1de/0x250 dev_change_flags+0x22/0x60 do_setlink.isra.0+0x2df/0x10b0 ? rtnetlink_rcv_msg+0x34f/0x3f0 ? netlink_rcv_skb+0x54/0x100 ? netlink_unicast+0x23e/0x390 ? netlink_sendmsg+0x21e/0x490 ? ____sys_sendmsg+0x31b/0x350 ? avc_has_perm_noaudit+0x67/0xf0 ? cred_has_capability.isra.0+0x75/0x110 ? __nla_validate_parse+0x5f/0xee0 ? __pfx___probestub_irq_enable+0x3/0x10 ? __create_object+0x5e/0x90 ? security_capable+0x3b/0x7[I0 rtnl_newlink+0x784/0xaf0 ? avc_has_perm_noaudit+0x67/0xf0 ? cred_has_capability.isra.0+0x75/0x110 ? stack_depot_save_flags+0x24/0x6d0 ? __pfx_rtnl_newlink+0x10/0x10 rtnetlink_rcv_msg+0x34f/0x3f0 ? do_syscall_64+0x6c/0x180 ? entry_SYSCALL_64_after_hwframe+0x76/0x7e ? __pfx_rtnetlink_rcv_msg+0x10/0x10 netlink_rcv_skb+0x54/0x100 netlink_unicast+0x23e/0x390 netlink_sendmsg+0x21e/0x490 ____sys_sendmsg+0x31b/0x350 ? copy_msghdr_from_user+0x6d/0xa0 ___sys_sendmsg+0x86/0xd0 ? __pte_offset_map+0x17/0x160 ? preempt_count_add+0x69/0xa0 ? __call_rcu_common.constprop.0+0x147/0x610 ? preempt_count_add+0x69/0xa0 ? preempt_count_add+0x69/0xa0 ? _raw_spin_trylock+0x13/0x60 ? trace_hardirqs_on+0x1d/0x80 __sys_sendmsg+0x66/0xc0 do_syscall_64+0x6c/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f41defe5b34 Code: 15 e1 12 0f 00 f7 d8 64 89 02 b8 ff ff ff ff eb bf 0f 1f 44 00 00 f3 0f 1e fa 80 3d 35 95 0f 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 4c c3 0f 1f 00 55 48 89 e5 48 83 ec 20 89 55 RSP: 002b:00007ffe5336ecc8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f41defe5b34 RDX: 0000000000000000 RSI: 00007ffe5336ed30 RDI: 0000000000000003 RBP: 00007ffe5336eda0 R08: 0000000000000010 R09: 0000000000000001 R10: 00007ffe5336f6f9 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000067452259 R14: 0000556ccc28b040 R15: 0000000000000000 </TASK> [...] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- Koichiro Den (5): virtio_net: correct netdev_tx_reset_queue() invocation point virtio_ring: add 'flushed' as an argument to virtqueue_resize() virtio_net: add missing netdev_tx_reset_queue() to virtnet_tx_resize() virtio_ring: add 'flushed' as an argument to virtqueue_reset() virtio_net: add missing netdev_tx_reset_queue to virtnet_sq_bind_xsk_pool() drivers/net/virtio_net.c | 18 +++++++++++++----- drivers/virtio/virtio_ring.c | 13 +++++++++++-- include/linux/virtio.h | 6 ++++-- 3 files changed, 28 insertions(+), 9 deletions(-) -- 2.43.0

1 month, 3 weeks

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[PATCH] net: wireless: sme: Initialize n_channels before accessing channels in cfg80211_conn_scan

by Haoyu Li

With the new __counted_by annocation in cfg80211_scan_request struct, the "n_channels" struct member must be set before accessing the "channels" array. Failing to do so will trigger a runtime warning when enabling CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE. Fixes: e3eac9f32ec0 ("wifi: cfg80211: Annotate struct cfg80211_scan_request with __counted_by") Signed-off-by: Haoyu Li <lihaoyu499(a)gmail.com> --- net/wireless/sme.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/wireless/sme.c b/net/wireless/sme.c index 431da30817a6..268171600087 100644 --- a/net/wireless/sme.c +++ b/net/wireless/sme.c @@ -83,6 +83,7 @@ static int cfg80211_conn_scan(struct wireless_dev *wdev) if (!request) return -ENOMEM; + request->n_channels = n_channels; if (wdev->conn->params.channel) { enum nl80211_band band = wdev->conn->params.channel->band; struct ieee80211_supported_band *sband = -- 2.34.1

1 month, 3 weeks

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[net] net: Make napi_hash_lock irq safe

by Joe Damato

Make napi_hash_lock IRQ safe. It is used during the control path, and is taken and released in napi_hash_add and napi_hash_del, which will typically be called by calls to napi_enable and napi_disable. This change avoids a deadlock in pcnet32 (and other any other drivers which follow the same pattern): CPU 0: pcnet32_open spin_lock_irqsave(&lp->lock, ...) napi_enable napi_hash_add <- before this executes, CPU 1 proceeds spin_lock(napi_hash_lock) [...] spin_unlock_irqrestore(&lp->lock, flags); CPU 1: pcnet32_close napi_disable napi_hash_del spin_lock(napi_hash_lock) < INTERRUPT > pcnet32_interrupt spin_lock(lp->lock) <- DEADLOCK Changing the napi_hash_lock to be IRQ safe prevents the IRQ from firing on CPU 1 until napi_hash_lock is released, preventing the deadlock. Cc: stable(a)vger.kernel.org Fixes: 86e25f40aa1e ("net: napi: Add napi_config") Reported-by: Guenter Roeck <linux(a)roeck-us.net> Closes: https://lore.kernel.org/netdev/85dd4590-ea6b-427d-876a-1d8559c7ad82@roeck-u… Suggested-by: Jakub Kicinski <kuba(a)kernel.org> Signed-off-by: Joe Damato <jdamato(a)fastly.com> --- net/core/dev.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 13d00fc10f55..45a8c3dd4a64 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6557,18 +6557,22 @@ static void __napi_hash_add_with_id(struct napi_struct *napi, static void napi_hash_add_with_id(struct napi_struct *napi, unsigned int napi_id) { - spin_lock(&napi_hash_lock); + unsigned long flags; + + spin_lock_irqsave(&napi_hash_lock, flags); WARN_ON_ONCE(napi_by_id(napi_id)); __napi_hash_add_with_id(napi, napi_id); - spin_unlock(&napi_hash_lock); + spin_unlock_irqrestore(&napi_hash_lock, flags); } static void napi_hash_add(struct napi_struct *napi) { + unsigned long flags; + if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state)) return; - spin_lock(&napi_hash_lock); + spin_lock_irqsave(&napi_hash_lock, flags); /* 0..NR_CPUS range is reserved for sender_cpu use */ do { @@ -6578,7 +6582,7 @@ static void napi_hash_add(struct napi_struct *napi) __napi_hash_add_with_id(napi, napi_gen_id); - spin_unlock(&napi_hash_lock); + spin_unlock_irqrestore(&napi_hash_lock, flags); } /* Warning : caller is responsible to make sure rcu grace period @@ -6586,11 +6590,13 @@ static void napi_hash_add(struct napi_struct *napi) */ static void napi_hash_del(struct napi_struct *napi) { - spin_lock(&napi_hash_lock); + unsigned long flags; + + spin_lock_irqsave(&napi_hash_lock, flags); hlist_del_init_rcu(&napi->napi_hash_node); - spin_unlock(&napi_hash_lock); + spin_unlock_irqrestore(&napi_hash_lock, flags); } static enum hrtimer_restart napi_watchdog(struct hrtimer *timer) -- 2.25.1

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