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CVE-2024-49884— ext4: fix slab-use-after-free in ext4_split_extent_at()

EPSS 0.01% · P2
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I. Basic Information for CVE-2024-49884

Vulnerability Information
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Vulnerability Title
ext4: fix slab-use-after-free in ext4_split_extent_at()
Source: NVD (National Vulnerability Database)
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: ext4: fix slab-use-after-free in ext4_split_extent_at() We hit the following use-after-free: ================================================================== BUG: KASAN: slab-use-after-free in ext4_split_extent_at+0xba8/0xcc0 Read of size 2 at addr ffff88810548ed08 by task kworker/u20:0/40 CPU: 0 PID: 40 Comm: kworker/u20:0 Not tainted 6.9.0-dirty #724 Call Trace: <TASK> kasan_report+0x93/0xc0 ext4_split_extent_at+0xba8/0xcc0 ext4_split_extent.isra.0+0x18f/0x500 ext4_split_convert_extents+0x275/0x750 ext4_ext_handle_unwritten_extents+0x73e/0x1580 ext4_ext_map_blocks+0xe20/0x2dc0 ext4_map_blocks+0x724/0x1700 ext4_do_writepages+0x12d6/0x2a70 [...] Allocated by task 40: __kmalloc_noprof+0x1ac/0x480 ext4_find_extent+0xf3b/0x1e70 ext4_ext_map_blocks+0x188/0x2dc0 ext4_map_blocks+0x724/0x1700 ext4_do_writepages+0x12d6/0x2a70 [...] Freed by task 40: kfree+0xf1/0x2b0 ext4_find_extent+0xa71/0x1e70 ext4_ext_insert_extent+0xa22/0x3260 ext4_split_extent_at+0x3ef/0xcc0 ext4_split_extent.isra.0+0x18f/0x500 ext4_split_convert_extents+0x275/0x750 ext4_ext_handle_unwritten_extents+0x73e/0x1580 ext4_ext_map_blocks+0xe20/0x2dc0 ext4_map_blocks+0x724/0x1700 ext4_do_writepages+0x12d6/0x2a70 [...] ================================================================== The flow of issue triggering is as follows: ext4_split_extent_at path = *ppath ext4_ext_insert_extent(ppath) ext4_ext_create_new_leaf(ppath) ext4_find_extent(orig_path) path = *orig_path read_extent_tree_block // return -ENOMEM or -EIO ext4_free_ext_path(path) kfree(path) *orig_path = NULL a. If err is -ENOMEM: ext4_ext_dirty(path + path->p_depth) // path use-after-free !!! b. If err is -EIO and we have EXT_DEBUG defined: ext4_ext_show_leaf(path) eh = path[depth].p_hdr // path also use-after-free !!! So when trying to zeroout or fix the extent length, call ext4_find_extent() to update the path. In addition we use *ppath directly as an ext4_ext_show_leaf() input to avoid possible use-after-free when EXT_DEBUG is defined, and to avoid unnecessary path updates.
Source: NVD (National Vulnerability Database)
CVSS Information
N/A
Source: NVD (National Vulnerability Database)
Vulnerability Type
N/A
Source: NVD (National Vulnerability Database)
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于ext4文件系统在ext4_split_extent_at函数中对已释放内存的不当访问，导致释放后重用问题。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

VendorProductAffected VersionsCPESubscribe
LinuxLinux dfe5080939ea4686b3414b5d970a9b26733c57a4 ~ 393a46f60ea4f249dc9d496d4eb2d542f5e11ade -
LinuxLinux 3.18 -

II. Public POCs for CVE-2024-49884

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III. Intelligence Information for CVE-2024-49884

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Same Patch Batch · Linux · 2024-10-21 · 372 CVEs total

CVE-2024-50019kthread: unpark only parked kthread
CVE-2024-50030drm/xe/ct: prevent UAF in send_recv()
CVE-2024-50028thermal: core: Reference count the zone in thermal_zone_get_by_id()
CVE-2024-50029Bluetooth: hci_conn: Fix UAF in hci_enhanced_setup_sync
CVE-2024-50027thermal: core: Free tzp copy along with the thermal zone
CVE-2024-50025scsi: fnic: Move flush_work initialization out of if block
CVE-2024-50026scsi: wd33c93: Don't use stale scsi_pointer value
CVE-2024-50023net: phy: Remove LED entry from LEDs list on unregister
CVE-2024-50024net: Fix an unsafe loop on the list
CVE-2024-50022device-dax: correct pgoff align in dax_set_mapping()
CVE-2024-50021ice: Fix improper handling of refcount in ice_dpll_init_rclk_pins()
CVE-2024-50020ice: Fix improper handling of refcount in ice_sriov_set_msix_vec_count()
CVE-2024-50011ASoC: Intel: soc-acpi-intel-rpl-match: add missing empty item
CVE-2024-50006ext4: fix i_data_sem unlock order in ext4_ind_migrate()
CVE-2024-50007ALSA: asihpi: Fix potential OOB array access
CVE-2024-50008wifi: mwifiex: Fix memcpy() field-spanning write warning in mwifiex_cmd_802_11_scan_ext()
CVE-2024-50009cpufreq: amd-pstate: add check for cpufreq_cpu_get's return value
CVE-2024-50010exec: don't WARN for racy path_noexec check
CVE-2024-50014ext4: fix access to uninitialised lock in fc replay path
CVE-2024-50017x86/mm/ident_map: Use gbpages only where full GB page should be mapped.

Showing top 20 of 372 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

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