Search Results (8505 CVEs found)

CVE Vendors Products Updated CVSS v3.1
CVE-2025-71196 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: phy: stm32-usphyc: Fix off by one in probe() The "index" variable is used as an index into the usbphyc->phys[] array which has usbphyc->nphys elements. So if it is equal to usbphyc->nphys then it is one element out of bounds. The "index" comes from the device tree so it's data that we trust and it's unlikely to be wrong, however it's obviously still worth fixing the bug. Change the > to >=.
CVE-2025-68752 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: iavf: Implement settime64 with -EOPNOTSUPP ptp_clock_settime() assumes every ptp_clock has implemented settime64(). Stub it with -EOPNOTSUPP to prevent a NULL dereference. The fix is similar to commit 329d050bbe63 ("gve: Implement settime64 with -EOPNOTSUPP").
CVE-2025-71195 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: dmaengine: xilinx: xdma: Fix regmap max_register The max_register field is assigned the size of the register memory region instead of the offset of the last register. The result is that reading from the regmap via debugfs can cause a segmentation fault: tail /sys/kernel/debug/regmap/xdma.1.auto/registers Unable to handle kernel paging request at virtual address ffff800082f70000 Mem abort info: ESR = 0x0000000096000007 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x07: level 3 translation fault [...] Call trace: regmap_mmio_read32le+0x10/0x30 _regmap_bus_reg_read+0x74/0xc0 _regmap_read+0x68/0x198 regmap_read+0x54/0x88 regmap_read_debugfs+0x140/0x380 regmap_map_read_file+0x30/0x48 full_proxy_read+0x68/0xc8 vfs_read+0xcc/0x310 ksys_read+0x7c/0x120 __arm64_sys_read+0x24/0x40 invoke_syscall.constprop.0+0x64/0x108 do_el0_svc+0xb0/0xd8 el0_svc+0x38/0x130 el0t_64_sync_handler+0x120/0x138 el0t_64_sync+0x194/0x198 Code: aa1e03e9 d503201f f9400000 8b214000 (b9400000) ---[ end trace 0000000000000000 ]--- note: tail[1217] exited with irqs disabled note: tail[1217] exited with preempt_count 1 Segmentation fault
CVE-2025-71065 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid potential deadlock As Jiaming Zhang and syzbot reported, there is potential deadlock in f2fs as below: Chain exists of: &sbi->cp_rwsem --> fs_reclaim --> sb_internal#2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(sb_internal#2); lock(fs_reclaim); lock(sb_internal#2); rlock(&sbi->cp_rwsem); *** DEADLOCK *** 3 locks held by kswapd0/73: #0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:7015 [inline] #0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x951/0x2800 mm/vmscan.c:7389 #1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:562 [inline] #1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_cache_scan+0x91/0x4b0 fs/super.c:197 #2: ffff888011840610 (sb_internal#2){.+.+}-{0:0}, at: f2fs_evict_inode+0x8d9/0x1b60 fs/f2fs/inode.c:890 stack backtrace: CPU: 0 UID: 0 PID: 73 Comm: kswapd0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1537 f2fs_down_read fs/f2fs/f2fs.h:2278 [inline] f2fs_lock_op fs/f2fs/f2fs.h:2357 [inline] f2fs_do_truncate_blocks+0x21c/0x10c0 fs/f2fs/file.c:791 f2fs_truncate_blocks+0x10a/0x300 fs/f2fs/file.c:867 f2fs_truncate+0x489/0x7c0 fs/f2fs/file.c:925 f2fs_evict_inode+0x9f2/0x1b60 fs/f2fs/inode.c:897 evict+0x504/0x9c0 fs/inode.c:810 f2fs_evict_inode+0x1dc/0x1b60 fs/f2fs/inode.c:853 evict+0x504/0x9c0 fs/inode.c:810 dispose_list fs/inode.c:852 [inline] prune_icache_sb+0x21b/0x2c0 fs/inode.c:1000 super_cache_scan+0x39b/0x4b0 fs/super.c:224 do_shrink_slab+0x6ef/0x1110 mm/shrinker.c:437 shrink_slab_memcg mm/shrinker.c:550 [inline] shrink_slab+0x7ef/0x10d0 mm/shrinker.c:628 shrink_one+0x28a/0x7c0 mm/vmscan.c:4955 shrink_many mm/vmscan.c:5016 [inline] lru_gen_shrink_node mm/vmscan.c:5094 [inline] shrink_node+0x315d/0x3780 mm/vmscan.c:6081 kswapd_shrink_node mm/vmscan.c:6941 [inline] balance_pgdat mm/vmscan.c:7124 [inline] kswapd+0x147c/0x2800 mm/vmscan.c:7389 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> The root cause is deadlock among four locks as below: kswapd - fs_reclaim --- Lock A - shrink_one - evict - f2fs_evict_inode - sb_start_intwrite --- Lock B - iput - evict - f2fs_evict_inode - sb_start_intwrite --- Lock B - f2fs_truncate - f2fs_truncate_blocks - f2fs_do_truncate_blocks - f2fs_lock_op --- Lock C ioctl - f2fs_ioc_commit_atomic_write - f2fs_lock_op --- Lock C - __f2fs_commit_atomic_write - __replace_atomic_write_block - f2fs_get_dnode_of_data - __get_node_folio - f2fs_check_nid_range - f2fs_handle_error - f2fs_record_errors - f2fs_down_write --- Lock D open - do_open - do_truncate - security_inode_need_killpriv - f2fs_getxattr - lookup_all_xattrs - f2fs_handle_error - f2fs_record_errors - f2fs_down_write --- Lock D - f2fs_commit_super - read_mapping_folio - filemap_alloc_folio_noprof - prepare_alloc_pages - fs_reclaim_acquire --- Lock A In order to a ---truncated---
CVE-2025-68754 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: rtc: amlogic-a4: fix double free caused by devm The clock obtained via devm_clk_get_enabled() is automatically managed by devres and will be disabled and freed on driver detach. Manually calling clk_disable_unprepare() in error path and remove function causes double free. Remove the redundant clk_disable_unprepare() calls from the probe error path and aml_rtc_remove(), allowing the devm framework to automatically manage the clock lifecycle.
CVE-2025-68763 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: crypto: starfive - Correctly handle return of sg_nents_for_len The return value of sg_nents_for_len was assigned to an unsigned long in starfive_hash_digest, causing negative error codes to be converted to large positive integers. Add error checking for sg_nents_for_len and return immediately on failure to prevent potential buffer overflows.
CVE-2025-68766 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: irqchip/mchp-eic: Fix error code in mchp_eic_domain_alloc() If irq_domain_translate_twocell() sets "hwirq" to >= MCHP_EIC_NIRQ (2) then it results in an out of bounds access. The code checks for invalid values, but doesn't set the error code. Return -EINVAL in that case, instead of returning success.
CVE-2025-68776 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: net/hsr: fix NULL pointer dereference in prp_get_untagged_frame() prp_get_untagged_frame() calls __pskb_copy() to create frame->skb_std but doesn't check if the allocation failed. If __pskb_copy() returns NULL, skb_clone() is called with a NULL pointer, causing a crash: Oops: general protection fault, probably for non-canonical address 0xdffffc000000000f: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f] CPU: 0 UID: 0 PID: 5625 Comm: syz.1.18 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:skb_clone+0xd7/0x3a0 net/core/skbuff.c:2041 Code: 03 42 80 3c 20 00 74 08 4c 89 f7 e8 23 29 05 f9 49 83 3e 00 0f 85 a0 01 00 00 e8 94 dd 9d f8 48 8d 6b 7e 49 89 ee 49 c1 ee 03 <43> 0f b6 04 26 84 c0 0f 85 d1 01 00 00 44 0f b6 7d 00 41 83 e7 0c RSP: 0018:ffffc9000d00f200 EFLAGS: 00010207 RAX: ffffffff892235a1 RBX: 0000000000000000 RCX: ffff88803372a480 RDX: 0000000000000000 RSI: 0000000000000820 RDI: 0000000000000000 RBP: 000000000000007e R08: ffffffff8f7d0f77 R09: 1ffffffff1efa1ee R10: dffffc0000000000 R11: fffffbfff1efa1ef R12: dffffc0000000000 R13: 0000000000000820 R14: 000000000000000f R15: ffff88805144cc00 FS: 0000555557f6d500(0000) GS:ffff88808d72f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555581d35808 CR3: 000000005040e000 CR4: 0000000000352ef0 Call Trace: <TASK> hsr_forward_do net/hsr/hsr_forward.c:-1 [inline] hsr_forward_skb+0x1013/0x2860 net/hsr/hsr_forward.c:741 hsr_handle_frame+0x6ce/0xa70 net/hsr/hsr_slave.c:84 __netif_receive_skb_core+0x10b9/0x4380 net/core/dev.c:5966 __netif_receive_skb_one_core net/core/dev.c:6077 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6192 netif_receive_skb_internal net/core/dev.c:6278 [inline] netif_receive_skb+0x1cb/0x790 net/core/dev.c:6337 tun_rx_batched+0x1b9/0x730 drivers/net/tun.c:1485 tun_get_user+0x2b65/0x3e90 drivers/net/tun.c:1953 tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0449f8e1ff Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48 RSP: 002b:00007ffd7ad94c90 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f044a1e5fa0 RCX: 00007f0449f8e1ff RDX: 000000000000003e RSI: 0000200000000500 RDI: 00000000000000c8 RBP: 00007ffd7ad94d20 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000003e R11: 0000000000000293 R12: 0000000000000001 R13: 00007f044a1e5fa0 R14: 00007f044a1e5fa0 R15: 0000000000000003 </TASK> Add a NULL check immediately after __pskb_copy() to handle allocation failures gracefully.
CVE-2025-68771 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix kernel BUG in ocfs2_find_victim_chain syzbot reported a kernel BUG in ocfs2_find_victim_chain() because the `cl_next_free_rec` field of the allocation chain list (next free slot in the chain list) is 0, triggring the BUG_ON(!cl->cl_next_free_rec) condition in ocfs2_find_victim_chain() and panicking the kernel. To fix this, an if condition is introduced in ocfs2_claim_suballoc_bits(), just before calling ocfs2_find_victim_chain(), the code block in it being executed when either of the following conditions is true: 1. `cl_next_free_rec` is equal to 0, indicating that there are no free chains in the allocation chain list 2. `cl_next_free_rec` is greater than `cl_count` (the total number of chains in the allocation chain list) Either of them being true is indicative of the fact that there are no chains left for usage. This is addressed using ocfs2_error(), which prints the error log for debugging purposes, rather than panicking the kernel.
CVE-2025-68773 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: spi: fsl-cpm: Check length parity before switching to 16 bit mode Commit fc96ec826bce ("spi: fsl-cpm: Use 16 bit mode for large transfers with even size") failed to make sure that the size is really even before switching to 16 bit mode. Until recently the problem went unnoticed because kernfs uses a pre-allocated bounce buffer of size PAGE_SIZE for reading EEPROM. But commit 8ad6249c51d0 ("eeprom: at25: convert to spi-mem API") introduced an additional dynamically allocated bounce buffer whose size is exactly the size of the transfer, leading to a buffer overrun in the fsl-cpm driver when that size is odd. Add the missing length parity verification and remain in 8 bit mode when the length is not even.
CVE-2025-68777 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: Input: ti_am335x_tsc - fix off-by-one error in wire_order validation The current validation 'wire_order[i] > ARRAY_SIZE(config_pins)' allows wire_order[i] to equal ARRAY_SIZE(config_pins), which causes out-of-bounds access when used as index in 'config_pins[wire_order[i]]'. Since config_pins has 4 elements (indices 0-3), the valid range for wire_order should be 0-3. Fix the off-by-one error by using >= instead of > in the validation check.
CVE-2025-68779 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Avoid unregistering PSP twice PSP is unregistered twice in: _mlx5e_remove -> mlx5e_psp_unregister mlx5e_nic_cleanup -> mlx5e_psp_unregister This leads to a refcount underflow in some conditions: ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 2 PID: 1694 at lib/refcount.c:28 refcount_warn_saturate+0xd8/0xe0 [...] mlx5e_psp_unregister+0x26/0x50 [mlx5_core] mlx5e_nic_cleanup+0x26/0x90 [mlx5_core] mlx5e_remove+0xe6/0x1f0 [mlx5_core] auxiliary_bus_remove+0x18/0x30 device_release_driver_internal+0x194/0x1f0 bus_remove_device+0xc6/0x130 device_del+0x159/0x3c0 mlx5_rescan_drivers_locked+0xbc/0x2a0 [mlx5_core] [...] Do not directly remove psp from the _mlx5e_remove path, the PSP cleanup happens as part of profile cleanup.
CVE-2025-68804 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: platform/chrome: cros_ec_ishtp: Fix UAF after unbinding driver After unbinding the driver, another kthread `cros_ec_console_log_work` is still accessing the device, resulting an UAF and crash. The driver doesn't unregister the EC device in .remove() which should shutdown sub-devices synchronously. Fix it.
CVE-2025-71199 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: iio: adc: at91-sama5d2_adc: Fix potential use-after-free in sama5d2_adc driver at91_adc_interrupt can call at91_adc_touch_data_handler function to start the work by schedule_work(&st->touch_st.workq). If we remove the module which will call at91_adc_remove to make cleanup, it will free indio_dev through iio_device_unregister but quite a bit later. While the work mentioned above will be used. The sequence of operations that may lead to a UAF bug is as follows: CPU0 CPU1 | at91_adc_workq_handler at91_adc_remove | iio_device_unregister(indio_dev) | //free indio_dev a bit later | | iio_push_to_buffers(indio_dev) | //use indio_dev Fix it by ensuring that the work is canceled before proceeding with the cleanup in at91_adc_remove.
CVE-2025-71198 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: iio: imu: st_lsm6dsx: fix iio_chan_spec for sensors without event detection The st_lsm6dsx_acc_channels array of struct iio_chan_spec has a non-NULL event_spec field, indicating support for IIO events. However, event detection is not supported for all sensors, and if userspace tries to configure accelerometer wakeup events on a sensor device that does not support them (e.g. LSM6DS0), st_lsm6dsx_write_event() dereferences a NULL pointer when trying to write to the wakeup register. Define an additional struct iio_chan_spec array whose members have a NULL event_spec field, and use this array instead of st_lsm6dsx_acc_channels for sensors without event detection capability.
CVE-2025-71197 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: w1: therm: Fix off-by-one buffer overflow in alarms_store The sysfs buffer passed to alarms_store() is allocated with 'size + 1' bytes and a NUL terminator is appended. However, the 'size' argument does not account for this extra byte. The original code then allocated 'size' bytes and used strcpy() to copy 'buf', which always writes one byte past the allocated buffer since strcpy() copies until the NUL terminator at index 'size'. Fix this by parsing the 'buf' parameter directly using simple_strtoll() without allocating any intermediate memory or string copying. This removes the overflow while simplifying the code.
CVE-2025-71067 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: ntfs: set dummy blocksize to read boot_block when mounting When mounting, sb->s_blocksize is used to read the boot_block without being defined or validated. Set a dummy blocksize before attempting to read the boot_block. The issue can be triggered with the following syz reproducer: mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./file1\x00', 0x0) r4 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x121403, 0x0) ioctl$FS_IOC_SETFLAGS(r4, 0x40081271, &(0x7f0000000980)=0x4000) mount(&(0x7f0000000140)=@nullb, &(0x7f0000000040)='./cgroup\x00', &(0x7f0000000000)='ntfs3\x00', 0x2208004, 0x0) syz_clone(0x88200200, 0x0, 0x0, 0x0, 0x0, 0x0) Here, the ioctl sets the bdev block size to 16384. During mount, get_tree_bdev_flags() calls sb_set_blocksize(sb, block_size(bdev)), but since block_size(bdev) > PAGE_SIZE, sb_set_blocksize() leaves sb->s_blocksize at zero. Later, ntfs_init_from_boot() attempts to read the boot_block while sb->s_blocksize is still zero, which triggers the bug. [almaz.alexandrovich@paragon-software.com: changed comment style, added return value handling]
CVE-2025-68796 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid updating zero-sized extent in extent cache As syzbot reported: F2FS-fs (loop0): __update_extent_tree_range: extent len is zero, type: 0, extent [0, 0, 0], age [0, 0] ------------[ cut here ]------------ kernel BUG at fs/f2fs/extent_cache.c:678! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5336 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:__update_extent_tree_range+0x13bc/0x1500 fs/f2fs/extent_cache.c:678 Call Trace: <TASK> f2fs_update_read_extent_cache_range+0x192/0x3e0 fs/f2fs/extent_cache.c:1085 f2fs_do_zero_range fs/f2fs/file.c:1657 [inline] f2fs_zero_range+0x10c1/0x1580 fs/f2fs/file.c:1737 f2fs_fallocate+0x583/0x990 fs/f2fs/file.c:2030 vfs_fallocate+0x669/0x7e0 fs/open.c:342 ioctl_preallocate fs/ioctl.c:289 [inline] file_ioctl+0x611/0x780 fs/ioctl.c:-1 do_vfs_ioctl+0xb33/0x1430 fs/ioctl.c:576 __do_sys_ioctl fs/ioctl.c:595 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f07bc58eec9 In error path of f2fs_zero_range(), it may add a zero-sized extent into extent cache, it should be avoided.
CVE-2025-68791 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: fuse: missing copy_finish in fuse-over-io-uring argument copies Fix a possible reference count leak of payload pages during fuse argument copies. [Joanne: simplified error cleanup]
CVE-2025-68783 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-mixer: us16x08: validate meter packet indices get_meter_levels_from_urb() parses the 64-byte meter packets sent by the device and fills the per-channel arrays meter_level[], comp_level[] and master_level[] in struct snd_us16x08_meter_store. Currently the function derives the channel index directly from the meter packet (MUB2(meter_urb, s) - 1) and uses it to index those arrays without validating the range. If the packet contains a negative or out-of-range channel number, the driver may write past the end of these arrays. Introduce a local channel variable and validate it before updating the arrays. We reject negative indices, limit meter_level[] and comp_level[] to SND_US16X08_MAX_CHANNELS, and guard master_level[] updates with ARRAY_SIZE(master_level).