November 2022 - Linux-stable-mirror

RE: [PATCH] mm, compaction: fix fast_isolate_around() to stay within boundaries

by Akira Naribayashi (Fujitsu)

Sorry, I may not have sent the email correctly. I will resend it. On Thu, 27 Oct 2022 20:26:04 +0000 Andrew Morton <akpm(a)linux-foundation.org> wrote: > On Wed, 26 Oct 2022 20:24:38 +0900 NARIBAYASHI Akira <a.naribayashi(a)fujitsu.com> wrote: > > > Depending on the memory configuration, isolate_freepages_block() may > > scan pages out of the target range and causes panic. > > > > The problem is that pfn as argument of fast_isolate_around() could > > be out of the target range. Therefore we should consider the case > > where pfn < start_pfn, and also the case where end_pfn < pfn. > > > > This problem should have been addressd by the commit 6e2b7044c199 > > ("mm, compaction: make fast_isolate_freepages() stay within zone") > > but there was an oversight. > > > > Case1: pfn < start_pfn > > > > <at memory compaction for node Y> > > | node X's zone | node Y's zone > > +-----------------+------------------------------... > > pageblock ^ ^ ^ > > +-----------+-----------+-----------+-----------+... > > ^ ^ ^ > > ^ ^ end_pfn > > ^ start_pfn = cc->zone->zone_start_pfn > > pfn > > <---------> scanned range by "Scan After" > > > > Case2: end_pfn < pfn > > > > <at memory compaction for node X> > > | node X's zone | node Y's zone > > +-----------------+------------------------------... > > pageblock ^ ^ ^ > > +-----------+-----------+-----------+-----------+... > > ^ ^ ^ > > ^ ^ pfn > > ^ end_pfn > > start_pfn > > <---------> scanned range by "Scan Before" > > > > It seems that there is no good reason to skip nr_isolated pages > > just after given pfn. So let perform simple scan from start to end > > instead of dividing the scan into "Before" and "After". > > Under what circumstances will this panic occur? I assume those > circumstnces are pretty rare, give that 6e2b7044c1992 was nearly two > years ago. > > Did you consider the desirability of backporting this fix into earlier > kernels? Panic can occur on systems with multiple zones in a single pageblock. The reason it is rare is that it only happens in special configurations. Depending on how many similar systems there are, it may be a good idea to fix this problem for older kernels as well.

2 years

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[PATCH-tip] sched: Fix use-after-free bug in dup_user_cpus_ptr()

by Waiman Long

Since commit 07ec77a1d4e8 ("sched: Allow task CPU affinity to be restricted on asymmetric systems"), the setting and clearing of user_cpus_ptr are done under pi_lock for arm64 architecture. However, dup_user_cpus_ptr() accesses user_cpus_ptr without any lock protection. When racing with the clearing of user_cpus_ptr in __set_cpus_allowed_ptr_locked(), it can lead to user-after-free and double-free in arm64 kernel. Commit 8f9ea86fdf99 ("sched: Always preserve the user requested cpumask") fixes this problem as user_cpus_ptr, once set, will never be cleared in a task's lifetime. However, this bug was re-introduced in commit 851a723e45d1 ("sched: Always clear user_cpus_ptr in do_set_cpus_allowed()") which allows the clearing of user_cpus_ptr in do_set_cpus_allowed(). This time, it will affect all arches. Fix this bug by always clearing the user_cpus_ptr of the newly cloned/forked task before the copying process starts and check the user_cpus_ptr state of the source task under pi_lock. Note to stable, this patch won't be applicable to stable releases. Just copy the new dup_user_cpus_ptr() function over. Fixes: 07ec77a1d4e8 ("sched: Allow task CPU affinity to be restricted on asymmetric systems") Fixes: 851a723e45d1 ("sched: Always clear user_cpus_ptr in do_set_cpus_allowed()") CC: stable(a)vger.kernel.org Reported-by: David Wang 王标 <wangbiao3(a)xiaomi.com> Signed-off-by: Waiman Long <longman(a)redhat.com> --- kernel/sched/core.c | 32 ++++++++++++++++++++++++++++---- 1 file changed, 28 insertions(+), 4 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 8df51b08bb38..f2b75faaf71a 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2624,19 +2624,43 @@ void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) { + cpumask_t *user_mask; unsigned long flags; + /* + * Always clear dst->user_cpus_ptr first as their user_cpus_ptr's + * may differ by now due to racing. + */ + dst->user_cpus_ptr = NULL; + + /* + * This check is racy and losing the race is a valid situation. + * It is not worth the extra overhead of taking the pi_lock on + * every fork/clone. + */ if (!src->user_cpus_ptr) return 0; - dst->user_cpus_ptr = kmalloc_node(cpumask_size(), GFP_KERNEL, node); - if (!dst->user_cpus_ptr) + user_mask = kmalloc_node(cpumask_size(), GFP_KERNEL, node); + if (!user_mask) return -ENOMEM; - /* Use pi_lock to protect content of user_cpus_ptr */ + /* + * Use pi_lock to protect content of user_cpus_ptr + * + * Though unlikely, user_cpus_ptr can be reset to NULL by a concurrent + * do_set_cpus_allowed(). + */ raw_spin_lock_irqsave(&src->pi_lock, flags); - cpumask_copy(dst->user_cpus_ptr, src->user_cpus_ptr); + if (src->user_cpus_ptr) { + swap(dst->user_cpus_ptr, user_mask); + cpumask_copy(dst->user_cpus_ptr, src->user_cpus_ptr); + } raw_spin_unlock_irqrestore(&src->pi_lock, flags); + + if (unlikely(user_mask)) + kfree(user_mask); + return 0; } -- 2.31.1

2 years

3
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[PATCH 2/2 v3] ceph: add ceph_lock_info support for file_lock

by xiubli＠redhat.com

From: Xiubo Li <xiubli(a)redhat.com> When ceph releasing the file_lock it will try to get the inode pointer from the fl->fl_file, which the memory could already be released by another thread in filp_close(). Because in VFS layer the fl->fl_file doesn't increase the file's reference counter. Will switch to use ceph dedicate lock info to track the inode. And in ceph_fl_release_lock() we should skip all the operations if the fl->fl_u.ceph_fl.fl_inode is not set, which should come from the request file_lock. And we will set fl->fl_u.ceph_fl.fl_inode when inserting it to the inode lock list, which is when copying the lock. Cc: stable(a)vger.kernel.org Cc: Jeff Layton <jlayton(a)kernel.org> URL: https://tracker.ceph.com/issues/57986 Signed-off-by: Xiubo Li <xiubli(a)redhat.com> --- fs/ceph/locks.c | 20 ++++++++++++++++++-- include/linux/ceph/ceph_fs_fl.h | 17 +++++++++++++++++ include/linux/fs.h | 2 ++ 3 files changed, 37 insertions(+), 2 deletions(-) create mode 100644 include/linux/ceph/ceph_fs_fl.h diff --git a/fs/ceph/locks.c b/fs/ceph/locks.c index b191426bf880..621f38f10a88 100644 --- a/fs/ceph/locks.c +++ b/fs/ceph/locks.c @@ -34,18 +34,34 @@ static void ceph_fl_copy_lock(struct file_lock *dst, struct file_lock *src) { struct inode *inode = file_inode(dst->fl_file); atomic_inc(&ceph_inode(inode)->i_filelock_ref); + dst->fl_u.ceph_fl.fl_inode = igrab(inode); } +/* + * Do not use the 'fl->fl_file' in release function, which + * is possibly already released by another thread. + */ static void ceph_fl_release_lock(struct file_lock *fl) { - struct inode *inode = file_inode(fl->fl_file); - struct ceph_inode_info *ci = ceph_inode(inode); + struct inode *inode = fl->fl_u.ceph_fl.fl_inode; + struct ceph_inode_info *ci; + + /* + * If inode is NULL it should be a request file_lock, + * nothing we can do. + */ + if (!inode) + return; + + ci = ceph_inode(inode); if (atomic_dec_and_test(&ci->i_filelock_ref)) { /* clear error when all locks are released */ spin_lock(&ci->i_ceph_lock); ci->i_ceph_flags &= ~CEPH_I_ERROR_FILELOCK; spin_unlock(&ci->i_ceph_lock); } + fl->fl_u.ceph_fl.fl_inode = NULL; + iput(inode); } static const struct file_lock_operations ceph_fl_lock_ops = { diff --git a/include/linux/ceph/ceph_fs_fl.h b/include/linux/ceph/ceph_fs_fl.h new file mode 100644 index 000000000000..ad1cf96329f9 --- /dev/null +++ b/include/linux/ceph/ceph_fs_fl.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * ceph_fs_fl.h - Ceph lock info + * + * LGPL2 + */ + +#ifndef CEPH_FS_FL_H +#define CEPH_FS_FL_H + +#include <linux/fs.h> + +struct ceph_lock_info { + struct inode *fl_inode; +}; + +#endif diff --git a/include/linux/fs.h b/include/linux/fs.h index d6cb42b7e91c..2b03d5e375d7 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1066,6 +1066,7 @@ bool opens_in_grace(struct net *); /* that will die - we need it for nfs_lock_info */ #include <linux/nfs_fs_i.h> +#include <linux/ceph/ceph_fs_fl.h> /* * struct file_lock represents a generic "file lock". It's used to represent @@ -1119,6 +1120,7 @@ struct file_lock { int state; /* state of grant or error if -ve */ unsigned int debug_id; } afs; + struct ceph_lock_info ceph_fl; } fl_u; } __randomize_layout; -- 2.31.1

2 years

4
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[PATCH v3] char: tpm: Protect tpm_pm_suspend with locks

by Jason A. Donenfeld

From: Jan Dabros <jsd(a)semihalf.com> Currently tpm transactions are executed unconditionally in tpm_pm_suspend() function, which may lead to races with other tpm accessors in the system. Specifically, the hw_random tpm driver makes use of tpm_get_random(), and this function is called in a loop from a kthread, which means it's not frozen alongside userspace, and so can race with the work done during system suspend: [ 3.277834] tpm tpm0: tpm_transmit: tpm_recv: error -52 [ 3.278437] tpm tpm0: invalid TPM_STS.x 0xff, dumping stack for forensics [ 3.278445] CPU: 0 PID: 1 Comm: init Not tainted 6.1.0-rc5+ #135 [ 3.278450] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-20220807_005459-localhost 04/01/2014 [ 3.278453] Call Trace: [ 3.278458] <TASK> [ 3.278460] dump_stack_lvl+0x34/0x44 [ 3.278471] tpm_tis_status.cold+0x19/0x20 [ 3.278479] tpm_transmit+0x13b/0x390 [ 3.278489] tpm_transmit_cmd+0x20/0x80 [ 3.278496] tpm1_pm_suspend+0xa6/0x110 [ 3.278503] tpm_pm_suspend+0x53/0x80 [ 3.278510] __pnp_bus_suspend+0x35/0xe0 [ 3.278515] ? pnp_bus_freeze+0x10/0x10 [ 3.278519] __device_suspend+0x10f/0x350 Fix this by calling tpm_try_get_ops(), which itself is a wrapper around tpm_chip_start(), but takes the appropriate mutex. Signed-off-by: Jan Dabros <jsd(a)semihalf.com> Reported-by: Vlastimil Babka <vbabka(a)suse.cz> Tested-by: Jason A. Donenfeld <Jason(a)zx2c4.com> Tested-by: Vlastimil Babka <vbabka(a)suse.cz> Link: https://lore.kernel.org/all/c5ba47ef-393f-1fba-30bd-1230d1b4b592@suse.cz/ Cc: stable(a)vger.kernel.org Fixes: e891db1a18bf ("tpm: turn on TPM on suspend for TPM 1.x") [Jason: reworked commit message, added metadata] Signed-off-by: Jason A. Donenfeld <Jason(a)zx2c4.com> --- drivers/char/tpm/tpm-interface.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 1621ce818705..d69905233aff 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -401,13 +401,14 @@ int tpm_pm_suspend(struct device *dev) !pm_suspend_via_firmware()) goto suspended; - if (!tpm_chip_start(chip)) { + rc = tpm_try_get_ops(chip); + if (!rc) { if (chip->flags & TPM_CHIP_FLAG_TPM2) tpm2_shutdown(chip, TPM2_SU_STATE); else rc = tpm1_pm_suspend(chip, tpm_suspend_pcr); - tpm_chip_stop(chip); + tpm_put_ops(chip); } suspended: -- 2.38.1

2 years

5
10
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[PATCH] ext4: Fix deadlock due to mbcache entry corruption

by Jan Kara

When manipulating xattr blocks, we can deadlock infinitely looping inside ext4_xattr_block_set() where we constantly keep finding xattr block for reuse in mbcache but we are unable to reuse it because its reference count is too big. This happens because cache entry for the xattr block is marked as reusable (e_reusable set) although its reference count is too big. When this inconsistency happens, this inconsistent state is kept indefinitely and so ext4_xattr_block_set() keeps retrying indefinitely. The inconsistent state is caused by non-atomic update of e_reusable bit. e_reusable is part of a bitfield and e_reusable update can race with update of e_referenced bit in the same bitfield resulting in loss of one of the updates. Fix the problem by using atomic bitops instead. CC: stable(a)vger.kernel.org Fixes: 6048c64b2609 ("mbcache: add reusable flag to cache entries") Reported-and-tested-by: Jeremi Piotrowski <jpiotrowski(a)linux.microsoft.com> Reported-by: Thilo Fromm <t-lo(a)linux.microsoft.com> Link: https://lore.kernel.org/r/c77bf00f-4618-7149-56f1-b8d1664b9d07@linux.micros… Signed-off-by: Jan Kara <jack(a)suse.cz> --- fs/ext4/xattr.c | 4 ++-- fs/mbcache.c | 14 ++++++++------ include/linux/mbcache.h | 9 +++++++-- 3 files changed, 17 insertions(+), 10 deletions(-) diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 800ce5cdb9d2..08043aa72cf1 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -1281,7 +1281,7 @@ ext4_xattr_release_block(handle_t *handle, struct inode *inode, ce = mb_cache_entry_get(ea_block_cache, hash, bh->b_blocknr); if (ce) { - ce->e_reusable = 1; + set_bit(MBE_REUSABLE_B, &ce->e_flags); mb_cache_entry_put(ea_block_cache, ce); } } @@ -2042,7 +2042,7 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode, } BHDR(new_bh)->h_refcount = cpu_to_le32(ref); if (ref == EXT4_XATTR_REFCOUNT_MAX) - ce->e_reusable = 0; + clear_bit(MBE_REUSABLE_B, &ce->e_flags); ea_bdebug(new_bh, "reusing; refcount now=%d", ref); ext4_xattr_block_csum_set(inode, new_bh); diff --git a/fs/mbcache.c b/fs/mbcache.c index e272ad738faf..2a4b8b549e93 100644 --- a/fs/mbcache.c +++ b/fs/mbcache.c @@ -100,8 +100,9 @@ int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key, atomic_set(&entry->e_refcnt, 2); entry->e_key = key; entry->e_value = value; - entry->e_reusable = reusable; - entry->e_referenced = 0; + entry->e_flags = 0; + if (reusable) + set_bit(MBE_REUSABLE_B, &entry->e_flags); head = mb_cache_entry_head(cache, key); hlist_bl_lock(head); hlist_bl_for_each_entry(dup, dup_node, head, e_hash_list) { @@ -165,7 +166,8 @@ static struct mb_cache_entry *__entry_find(struct mb_cache *cache, while (node) { entry = hlist_bl_entry(node, struct mb_cache_entry, e_hash_list); - if (entry->e_key == key && entry->e_reusable && + if (entry->e_key == key && + test_bit(MBE_REUSABLE_B, &entry->e_flags) && atomic_inc_not_zero(&entry->e_refcnt)) goto out; node = node->next; @@ -284,7 +286,7 @@ EXPORT_SYMBOL(mb_cache_entry_delete_or_get); void mb_cache_entry_touch(struct mb_cache *cache, struct mb_cache_entry *entry) { - entry->e_referenced = 1; + set_bit(MBE_REFERENCED_B, &entry->e_flags); } EXPORT_SYMBOL(mb_cache_entry_touch); @@ -309,9 +311,9 @@ static unsigned long mb_cache_shrink(struct mb_cache *cache, entry = list_first_entry(&cache->c_list, struct mb_cache_entry, e_list); /* Drop initial hash reference if there is no user */ - if (entry->e_referenced || + if (test_bit(MBE_REFERENCED_B, &entry->e_flags) || atomic_cmpxchg(&entry->e_refcnt, 1, 0) != 1) { - entry->e_referenced = 0; + clear_bit(MBE_REFERENCED_B, &entry->e_flags); list_move_tail(&entry->e_list, &cache->c_list); continue; } diff --git a/include/linux/mbcache.h b/include/linux/mbcache.h index 2da63fd7b98f..97e64184767d 100644 --- a/include/linux/mbcache.h +++ b/include/linux/mbcache.h @@ -10,6 +10,12 @@ struct mb_cache; +/* Cache entry flags */ +enum { + MBE_REFERENCED_B = 0, + MBE_REUSABLE_B +}; + struct mb_cache_entry { /* List of entries in cache - protected by cache->c_list_lock */ struct list_head e_list; @@ -26,8 +32,7 @@ struct mb_cache_entry { atomic_t e_refcnt; /* Key in hash - stable during lifetime of the entry */ u32 e_key; - u32 e_referenced:1; - u32 e_reusable:1; + unsigned long e_flags; /* User provided value - stable during lifetime of the entry */ u64 e_value; }; -- 2.35.3

2 years

6
11
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[PATCH 3/9] bfq: Split shared queues on move between cgroups

by Jan Kara

When bfqq is shared by multiple processes it can happen that one of the processes gets moved to a different cgroup (or just starts submitting IO for different cgroup). In case that happens we need to split the merged bfqq as otherwise we will have IO for multiple cgroups in one bfqq and we will just account IO time to wrong entities etc. Similarly if the bfqq is scheduled to merge with another bfqq but the merge didn't happen yet, cancel the merge as it need not be valid anymore. CC: stable(a)vger.kernel.org Fixes: e21b7a0b9887 ("block, bfq: add full hierarchical scheduling and cgroups support") Signed-off-by: Jan Kara <jack(a)suse.cz> --- block/bfq-cgroup.c | 36 +++++++++++++++++++++++++++++++++--- block/bfq-iosched.c | 2 +- block/bfq-iosched.h | 1 + 3 files changed, 35 insertions(+), 4 deletions(-) diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index 420eda2589c0..9352f3cc2377 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -743,9 +743,39 @@ static struct bfq_group *__bfq_bic_change_cgroup(struct bfq_data *bfqd, } if (sync_bfqq) { - entity = &sync_bfqq->entity; - if (entity->sched_data != &bfqg->sched_data) - bfq_bfqq_move(bfqd, sync_bfqq, bfqg); + if (!sync_bfqq->new_bfqq && !bfq_bfqq_coop(sync_bfqq)) { + /* We are the only user of this bfqq, just move it */ + if (sync_bfqq->entity.sched_data != &bfqg->sched_data) + bfq_bfqq_move(bfqd, sync_bfqq, bfqg); + } else { + struct bfq_queue *bfqq; + + /* + * The queue was merged to a different queue. Check + * that the merge chain still belongs to the same + * cgroup. + */ + for (bfqq = sync_bfqq; bfqq; bfqq = bfqq->new_bfqq) + if (bfqq->entity.sched_data != + &bfqg->sched_data) + break; + if (bfqq) { + /* + * Some queue changed cgroup so the merge is + * not valid anymore. We cannot easily just + * cancel the merge (by clearing new_bfqq) as + * there may be other processes using this + * queue and holding refs to all queues below + * sync_bfqq->new_bfqq. Similarly if the merge + * already happened, we need to detach from + * bfqq now so that we cannot merge bio to a + * request from the old cgroup. + */ + bfq_put_cooperator(sync_bfqq); + bfq_release_process_ref(bfqd, sync_bfqq); + bic_set_bfqq(bic, NULL, 1); + } + } } return bfqg; diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 7d00b21ebe5d..89fe3f85eb3c 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -5315,7 +5315,7 @@ static void bfq_put_stable_ref(struct bfq_queue *bfqq) bfq_put_queue(bfqq); } -static void bfq_put_cooperator(struct bfq_queue *bfqq) +void bfq_put_cooperator(struct bfq_queue *bfqq) { struct bfq_queue *__bfqq, *next; diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index 3b83e3d1c2e5..a56763045d19 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -979,6 +979,7 @@ void bfq_weights_tree_remove(struct bfq_data *bfqd, void bfq_bfqq_expire(struct bfq_data *bfqd, struct bfq_queue *bfqq, bool compensate, enum bfqq_expiration reason); void bfq_put_queue(struct bfq_queue *bfqq); +void bfq_put_cooperator(struct bfq_queue *bfqq); void bfq_end_wr_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg); void bfq_release_process_ref(struct bfq_data *bfqd, struct bfq_queue *bfqq); void bfq_schedule_dispatch(struct bfq_data *bfqd); -- 2.34.1

2 years

2
3
0 0

[PATCH v2] powerpc/bpf/32: Fix Oops on tail call tests

by Christophe Leroy

test_bpf tail call tests end up as: test_bpf: #0 Tail call leaf jited:1 85 PASS test_bpf: #1 Tail call 2 jited:1 111 PASS test_bpf: #2 Tail call 3 jited:1 145 PASS test_bpf: #3 Tail call 4 jited:1 170 PASS test_bpf: #4 Tail call load/store leaf jited:1 190 PASS test_bpf: #5 Tail call load/store jited:1 BUG: Unable to handle kernel data access on write at 0xf1b4e000 Faulting instruction address: 0xbe86b710 Oops: Kernel access of bad area, sig: 11 [#1] BE PAGE_SIZE=4K MMU=Hash PowerMac Modules linked in: test_bpf(+) CPU: 0 PID: 97 Comm: insmod Not tainted 6.1.0-rc4+ #195 Hardware name: PowerMac3,1 750CL 0x87210 PowerMac NIP: be86b710 LR: be857e88 CTR: be86b704 REGS: f1b4df20 TRAP: 0300 Not tainted (6.1.0-rc4+) MSR: 00009032 <EE,ME,IR,DR,RI> CR: 28008242 XER: 00000000 DAR: f1b4e000 DSISR: 42000000 GPR00: 00000001 f1b4dfe0 c11d2280 00000000 00000000 00000000 00000002 00000000 GPR08: f1b4e000 be86b704 f1b4e000 00000000 00000000 100d816a f2440000 fe73baa8 GPR16: f2458000 00000000 c1941ae4 f1fe2248 00000045 c0de0000 f2458030 00000000 GPR24: 000003e8 0000000f f2458000 f1b4dc90 3e584b46 00000000 f24466a0 c1941a00 NIP [be86b710] 0xbe86b710 LR [be857e88] __run_one+0xec/0x264 [test_bpf] Call Trace: [f1b4dfe0] [00000002] 0x2 (unreliable) Instruction dump: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX ---[ end trace 0000000000000000 ]--- This is a tentative to write above the stack. The problem is encoutered with tests added by commit 38608ee7b690 ("bpf, tests: Add load store test case for tail call") This happens because tail call is done to a BPF prog with a different stack_depth. At the time being, the stack is kept as is when the caller tail calls its callee. But at exit, the callee restores the stack based on its own properties. Therefore here, at each run, r1 is erroneously increased by 32 - 16 = 16 bytes. This was done that way in order to pass the tail call count from caller to callee through the stack. As powerpc32 doesn't have a red zone in the stack, it was necessary the maintain the stack as is for the tail call. But it was not anticipated that the BPF frame size could be different. Let's take a new approach. Use register r4 to carry the tail call count during the tail call, and save it into the stack at function entry if required. This means the input parameter must be in r3, which is more correct as it is a 32 bits parameter, then tail call better match with normal BPF function entry, the down side being that we move that input parameter back and forth between r3 and r4. That can be optimised later. Doing that also has the advantage of maximising the common parts between tail calls and a normal function exit. With the fix, tail call tests are now successfull: test_bpf: #0 Tail call leaf jited:1 53 PASS test_bpf: #1 Tail call 2 jited:1 115 PASS test_bpf: #2 Tail call 3 jited:1 154 PASS test_bpf: #3 Tail call 4 jited:1 165 PASS test_bpf: #4 Tail call load/store leaf jited:1 101 PASS test_bpf: #5 Tail call load/store jited:1 141 PASS test_bpf: #6 Tail call error path, max count reached jited:1 994 PASS test_bpf: #7 Tail call count preserved across function calls jited:1 140975 PASS test_bpf: #8 Tail call error path, NULL target jited:1 110 PASS test_bpf: #9 Tail call error path, index out of range jited:1 69 PASS test_bpf: test_tail_calls: Summary: 10 PASSED, 0 FAILED, [10/10 JIT'ed] Suggested-by: Naveen N. Rao <naveen.n.rao(a)linux.vnet.ibm.com> Fixes: 51c66ad849a7 ("powerpc/bpf: Implement extended BPF on PPC32") Cc: stable(a)vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy(a)csgroup.eu> --- v2: Using r4 for tcc as suggested by Naveen. --- arch/powerpc/net/bpf_jit_comp32.c | 52 +++++++++++++------------------ 1 file changed, 21 insertions(+), 31 deletions(-) diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c index 43f1c76d48ce..a379b0ce19ff 100644 --- a/arch/powerpc/net/bpf_jit_comp32.c +++ b/arch/powerpc/net/bpf_jit_comp32.c @@ -113,23 +113,19 @@ void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx) { int i; - /* First arg comes in as a 32 bits pointer. */ - EMIT(PPC_RAW_MR(bpf_to_ppc(BPF_REG_1), _R3)); - EMIT(PPC_RAW_LI(bpf_to_ppc(BPF_REG_1) - 1, 0)); + /* Initialize tail_call_cnt, to be skipped if we do tail calls. */ + EMIT(PPC_RAW_LI(_R4, 0)); + +#define BPF_TAILCALL_PROLOGUE_SIZE 4 + EMIT(PPC_RAW_STWU(_R1, _R1, -BPF_PPC_STACKFRAME(ctx))); - /* - * Initialize tail_call_cnt in stack frame if we do tail calls. - * Otherwise, put in NOPs so that it can be skipped when we are - * invoked through a tail call. - */ if (ctx->seen & SEEN_TAILCALL) - EMIT(PPC_RAW_STW(bpf_to_ppc(BPF_REG_1) - 1, _R1, - bpf_jit_stack_offsetof(ctx, BPF_PPC_TC))); - else - EMIT(PPC_RAW_NOP()); + EMIT(PPC_RAW_STW(_R4, _R1, bpf_jit_stack_offsetof(ctx, BPF_PPC_TC))); -#define BPF_TAILCALL_PROLOGUE_SIZE 16 + /* First arg comes in as a 32 bits pointer. */ + EMIT(PPC_RAW_MR(bpf_to_ppc(BPF_REG_1), _R3)); + EMIT(PPC_RAW_LI(bpf_to_ppc(BPF_REG_1) - 1, 0)); /* * We need a stack frame, but we don't necessarily need to @@ -170,24 +166,24 @@ static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx for (i = BPF_PPC_NVR_MIN; i <= 31; i++) if (bpf_is_seen_register(ctx, i)) EMIT(PPC_RAW_LWZ(i, _R1, bpf_jit_stack_offsetof(ctx, i))); -} - -void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) -{ - EMIT(PPC_RAW_MR(_R3, bpf_to_ppc(BPF_REG_0))); - - bpf_jit_emit_common_epilogue(image, ctx); - - /* Tear down our stack frame */ if (ctx->seen & SEEN_FUNC) EMIT(PPC_RAW_LWZ(_R0, _R1, BPF_PPC_STACKFRAME(ctx) + PPC_LR_STKOFF)); + /* Tear down our stack frame */ EMIT(PPC_RAW_ADDI(_R1, _R1, BPF_PPC_STACKFRAME(ctx))); if (ctx->seen & SEEN_FUNC) EMIT(PPC_RAW_MTLR(_R0)); +} + +void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx) +{ + EMIT(PPC_RAW_MR(_R3, bpf_to_ppc(BPF_REG_0))); + + bpf_jit_emit_common_epilogue(image, ctx); + EMIT(PPC_RAW_BLR()); } @@ -244,7 +240,6 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o EMIT(PPC_RAW_RLWINM(_R3, b2p_index, 2, 0, 29)); EMIT(PPC_RAW_ADD(_R3, _R3, b2p_bpf_array)); EMIT(PPC_RAW_LWZ(_R3, _R3, offsetof(struct bpf_array, ptrs))); - EMIT(PPC_RAW_STW(_R0, _R1, bpf_jit_stack_offsetof(ctx, BPF_PPC_TC))); /* * if (prog == NULL) @@ -255,19 +250,14 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o /* goto *(prog->bpf_func + prologue_size); */ EMIT(PPC_RAW_LWZ(_R3, _R3, offsetof(struct bpf_prog, bpf_func))); - - if (ctx->seen & SEEN_FUNC) - EMIT(PPC_RAW_LWZ(_R0, _R1, BPF_PPC_STACKFRAME(ctx) + PPC_LR_STKOFF)); - EMIT(PPC_RAW_ADDIC(_R3, _R3, BPF_TAILCALL_PROLOGUE_SIZE)); - - if (ctx->seen & SEEN_FUNC) - EMIT(PPC_RAW_MTLR(_R0)); - EMIT(PPC_RAW_MTCTR(_R3)); EMIT(PPC_RAW_MR(_R3, bpf_to_ppc(BPF_REG_1))); + /* Put tail_call_cnt in r4 */ + EMIT(PPC_RAW_MR(_R4, _R0)); + /* tear restore NVRs, ... */ bpf_jit_emit_common_epilogue(image, ctx); -- 2.38.1

2 years

3
2
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[PATCH] ext4: don't allow journal inode to have encrypt flag

by Eric Biggers

From: Eric Biggers <ebiggers(a)google.com> Mounting a filesystem whose journal inode has the encrypt flag causes a NULL dereference in fscrypt_limit_io_blocks() when the 'inlinecrypt' mount option is used. The problem is that when jbd2_journal_init_inode() calls bmap(), it eventually finds its way into ext4_iomap_begin(), which calls fscrypt_limit_io_blocks(). fscrypt_limit_io_blocks() requires that if the inode is encrypted, then its encryption key must already be set up. That's not the case here, since the journal inode is never "opened" like a normal file would be. Hence the crash. A reproducer is: mkfs.ext4 -F /dev/vdb debugfs -w /dev/vdb -R "set_inode_field <8> flags 0x80808" mount /dev/vdb /mnt -o inlinecrypt To fix this, make ext4 consider journal inodes with the encrypt flag to be invalid. (Note, maybe other flags should be rejected on the journal inode too. For now, this is just the minimal fix for the above issue.) I've marked this as fixing the commit that introduced the call to fscrypt_limit_io_blocks(), since that's what made an actual crash start being possible. But this fix could be applied to any version of ext4 that supports the encrypt feature. Reported-by: syzbot+ba9dac45bc76c490b7c3(a)syzkaller.appspotmail.com Fixes: 38ea50daa7a4 ("ext4: support direct I/O with fscrypt using blk-crypto") Cc: stable(a)vger.kernel.org Signed-off-by: Eric Biggers <ebiggers(a)google.com> --- fs/ext4/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 7950904fbf04f..2274f730b87e5 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -5723,7 +5723,7 @@ static struct inode *ext4_get_journal_inode(struct super_block *sb, ext4_debug("Journal inode found at %p: %lld bytes\n", journal_inode, journal_inode->i_size); - if (!S_ISREG(journal_inode->i_mode)) { + if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) { ext4_msg(sb, KERN_ERR, "invalid journal inode"); iput(journal_inode); return NULL; base-commit: 8f71a2b3f435f29b787537d1abedaa7d8ebe6647 -- 2.38.1

2 years

2
3
0 0

[PATCH] soc: qcom: Select REMAP_MMIO for ICC_BWMON driver

by Manivannan Sadhasivam

ICC_BWMON driver uses REGMAP_MMIO for accessing the hardware registers. So select the dependency in Kconfig. Without this, there will be errors while building the driver with COMPILE_TEST only: ERROR: modpost: "__devm_regmap_init_mmio_clk" [drivers/soc/qcom/icc-bwmon.ko] undefined! make[1]: *** [scripts/Makefile.modpost:126: Module.symvers] Error 1 make: *** [Makefile:1944: modpost] Error 2 Cc: <stable(a)vger.kernel.org> # 6.0 Cc: Krzysztof Kozlowski <krzysztof.kozlowski(a)linaro.org> Fixes: b9c2ae6cac40 ("soc: qcom: icc-bwmon: Add bandwidth monitoring driver") Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org> --- drivers/soc/qcom/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig index 024e420f1bb7..75bfdb6f9705 100644 --- a/drivers/soc/qcom/Kconfig +++ b/drivers/soc/qcom/Kconfig @@ -236,6 +236,7 @@ config QCOM_ICC_BWMON tristate "QCOM Interconnect Bandwidth Monitor driver" depends on ARCH_QCOM || COMPILE_TEST select PM_OPP + select REGMAP_MMIO help Sets up driver monitoring bandwidth on various interconnects and based on that voting for interconnect bandwidth, adjusting their -- 2.25.1

2 years

3
2
0 0

[PATCH v2 1/2] drm/shmem-helper: Remove errant put in error path

by Rob Clark

From: Rob Clark <robdclark(a)chromium.org> drm_gem_shmem_mmap() doesn't own this reference, resulting in the GEM object getting prematurely freed leading to a later use-after-free. Link: https://syzkaller.appspot.com/bug?extid=c8ae65286134dd1b800d Reported-by: syzbot+c8ae65286134dd1b800d(a)syzkaller.appspotmail.com Fixes: 2194a63a818d ("drm: Add library for shmem backed GEM objects") Cc: stable(a)vger.kernel.org Signed-off-by: Rob Clark <robdclark(a)chromium.org> Reviewed-by: Daniel Vetter <daniel.vetter(a)ffwll.ch> --- drivers/gpu/drm/drm_gem_shmem_helper.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index 35138f8a375c..3b7b71391a4c 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -622,10 +622,8 @@ int drm_gem_shmem_mmap(struct drm_gem_shmem_object *shmem, struct vm_area_struct } ret = drm_gem_shmem_get_pages(shmem); - if (ret) { - drm_gem_vm_close(vma); + if (ret) return ret; - } vma->vm_flags |= VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); -- 2.38.1

2 years

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Linux-stable-mirror November 2022