Linux Kernel up to 6.1.41/6.4.6 generic/476 release_folio buffer overflow

Summaryinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.1.41/6.4.6. This affects the function release_folio of the file generic/476. Performing a manipulation results in buffer overflow. This vulnerability is reported as CVE-2023-53247. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.1.41/6.4.6. This affects the function release_folio of the file generic/476. The manipulation with an unknown input leads to a buffer overflow vulnerability. CWE is classifying the issue as CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: btrfs: set_page_extent_mapped after read_folio in btrfs_cont_expand While trying to get the subpage blocksize tests running, I hit the following panic on generic/476 assertion failed: PagePrivate(page) && page->private, in fs/btrfs/subpage.c:229 kernel BUG at fs/btrfs/subpage.c:229! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP CPU: 1 PID: 1453 Comm: fsstress Not tainted 6.4.0-rc7+ #12 Hardware name: QEMU KVM Virtual Machine, BIOS edk2-20230301gitf80f052277c8-26.fc38 03/01/2023 pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) pc : btrfs_subpage_assert+0xbc/0xf0 lr : btrfs_subpage_assert+0xbc/0xf0 Call trace: btrfs_subpage_assert+0xbc/0xf0 btrfs_subpage_clear_checked+0x38/0xc0 btrfs_page_clear_checked+0x48/0x98 btrfs_truncate_block+0x5d0/0x6a8 btrfs_cont_expand+0x5c/0x528 btrfs_write_check.isra.0+0xf8/0x150 btrfs_buffered_write+0xb4/0x760 btrfs_do_write_iter+0x2f8/0x4b0 btrfs_file_write_iter+0x1c/0x30 do_iter_readv_writev+0xc8/0x158 do_iter_write+0x9c/0x210 vfs_iter_write+0x24/0x40 iter_file_splice_write+0x224/0x390 direct_splice_actor+0x38/0x68 splice_direct_to_actor+0x12c/0x260 do_splice_direct+0x90/0xe8 generic_copy_file_range+0x50/0x90 vfs_copy_file_range+0x29c/0x470 __arm64_sys_copy_file_range+0xcc/0x498 invoke_syscall.constprop.0+0x80/0xd8 do_el0_svc+0x6c/0x168 el0_svc+0x50/0x1b0 el0t_64_sync_handler+0x114/0x120 el0t_64_sync+0x194/0x198 This happens because during btrfs_cont_expand we'll get a page, set it as mapped, and if it's not Uptodate we'll read it. However between the read and re-locking the page we could have called release_folio() on the page, but left the page in the file mapping. release_folio() can clear the page private, and thus further down we blow up when we go to modify the subpage bits. Fix this by putting the set_page_extent_mapped() after the read. This is safe because read_folio() will call set_page_extent_mapped() before it does the read, and then if we clear page private but leave it on the mapping we're completely safe re-setting set_page_extent_mapped(). With this patch I can now run generic/476 without panicing.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2023-53247 since 09/15/2025. The exploitability is told to be easy. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 01/11/2026).

Upgrading to version 6.1.42 or 6.4.7 eliminates this vulnerability. Applying the patch 0a5e0bc8e8618e32a6ca64450867628eb0a627bf/a5880e69cf7fe4a0bb1eabae02205352d1b59b7b/17b17fcd6d446b95904a6929c40012ee7f0afc0c is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-2053). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• IBM QRadar SIEM
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux
• Dell Secure Connect Gateway
• F5 F5OS

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.0
• 6.1.1
• 6.1.2
• 6.1.3
• 6.1.4
• 6.1.5
• 6.1.6
• 6.1.7
• 6.1.8
• 6.1.9
• 6.1.10
• 6.1.11
• 6.1.12
• 6.1.13
• 6.1.14
• 6.1.15
• 6.1.16
• 6.1.17
• 6.1.18
• 6.1.19
• 6.1.20
• 6.1.21
• 6.1.22
• 6.1.23
• 6.1.24
• 6.1.25
• 6.1.26
• 6.1.27
• 6.1.28
• 6.1.29
• 6.1.30
• 6.1.31
• 6.1.32
• 6.1.33
• 6.1.34
• 6.1.35
• 6.1.36
• 6.1.37
• 6.1.38
• 6.1.39
• 6.1.40
• 6.1.41
• 6.4.0
• 6.4.1
• 6.4.2
• 6.4.3
• 6.4.4
• 6.4.5
• 6.4.6

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Exploitinginfo

Threat Intelligenceinfo

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Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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