CVE-2025-38203

MEDIUM
Published Jul 4, 2025 Modified Dec 18, 2025 CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: jfs: Fix null-ptr-deref in jfs_ioc_trim [ Syzkaller Report ] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000087: 0000 [#1 KASAN: null-ptr-deref in range [0x0000000000000438-0x000000000000043f] CPU: 2 UID: 0 PID: 10614 Comm: syz-executor.0 Not tainted 6.13.0-rc6-gfbfd64d25c7a-dirty #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Sched_ext: serialise (enabled+all), task: runnable_at=-30ms RIP: 0010:jfs_ioc_trim+0x34b/0x8f0 Code: e7 e8 59 a4 87 fe 4d 8b 24 24 4d 8d bc 24 38 04 00 00 48 8d 93 90 82 fe ff 4c 89 ff 31 f6 RSP: 0018:ffffc900055f7cd0 EFLAGS: 00010206 RAX: 0000000000000087 RBX: 00005866a9e67ff8 RCX: 000000000000000a RDX: 0000000000000001 RSI: 0000000000000004 RDI: 0000000000000001 RBP: dffffc0000000000 R08: ffff88807c180003 R09: 1ffff1100f830000 R10: dffffc0000000000 R11: ffffed100f830001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000438 FS: 00007fe520225640(0000) GS:ffff8880b7e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005593c91b2c88 CR3: 000000014927c000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? __die_body+0x61/0xb0 ? die_addr+0xb1/0xe0 ? exc_general_protection+0x333/0x510 ? asm_exc_general_protection+0x26/0x30 ? jfs_ioc_trim+0x34b/0x8f0 jfs_ioctl+0x3c8/0x4f0 ? __pfx_jfs_ioctl+0x10/0x10 ? __pfx_jfs_ioctl+0x10/0x10 __se_sys_ioctl+0x269/0x350 ? __pfx___se_sys_ioctl+0x10/0x10 ? do_syscall_64+0xfb/0x210 do_syscall_64+0xee/0x210 ? syscall_exit_to_user_mode+0x1e0/0x330 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe51f4903ad Code: c3 e8 a7 2b 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d RSP: 002b:00007fe5202250c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe51f5cbf80 RCX: 00007fe51f4903ad RDX: 0000000020000680 RSI: 00000000c0185879 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe520225640 R13: 000000000000000e R14: 00007fe51f44fca0 R15: 00007fe52021d000 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:jfs_ioc_trim+0x34b/0x8f0 Code: e7 e8 59 a4 87 fe 4d 8b 24 24 4d 8d bc 24 38 04 00 00 48 8d 93 90 82 fe ff 4c 89 ff 31 f6 RSP: 0018:ffffc900055f7cd0 EFLAGS: 00010206 RAX: 0000000000000087 RBX: 00005866a9e67ff8 RCX: 000000000000000a RDX: 0000000000000001 RSI: 0000000000000004 RDI: 0000000000000001 RBP: dffffc0000000000 R08: ffff88807c180003 R09: 1ffff1100f830000 R10: dffffc0000000000 R11: ffffed100f830001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000438 FS: 00007fe520225640(0000) GS:ffff8880b7e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005593c91b2c88 CR3: 000000014927c000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Kernel panic - not syncing: Fatal exception [ Analysis ] We believe that we have found a concurrency bug in the `fs/jfs` module that results in a null pointer dereference. There is a closely related issue which has been fixed: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d6c1b3599b2feb5c7291f5ac3a36e5fa7cedb234 ... but, unfortunately, the accepted patch appears to still be susceptible to a null pointer dereference under some interleavings. To trigger the bug, we think that `JFS_SBI(ipbmap->i_sb)->bmap` is set to NULL in `dbFreeBits` and then dereferenced in `jfs_ioc_trim`. This bug manifests quite rarely under normal circumstances, but is triggereable from a syz-program.

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CVSS v3.1 Score

5.5
MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-476 CWE-476

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
debian debian_linux

References

Frequently Asked Questions

What is CVE-2025-38203? +
In the Linux kernel, the following vulnerability has been resolved: jfs: Fix null-ptr-deref in jfs_ioc_trim [ Syzkaller Report ] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000087: 0000 [#1 KASAN: null-ptr-deref in range [0x0000000000000438-0x000000000000043f] CPU: 2 UID: 0 PID: 10614 Comm: syz-executor.0 Not tainted 6.13.0-rc6-gfbfd64d25c7a-dirty #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Sched_ext: serialise (enabled+all), task: runnable_at=-30ms RIP: 0010:jfs_ioc_trim+0x34b/0x8f0 Code: e7 e8 59 a4 87 fe 4d 8b 24 24 4d 8d bc 24 38 04 00 00 48 8d 93 90 82 fe ff 4c 89 ff 31 f6 RSP: 0018:ffffc900055f7cd0 EFLAGS: 00010206 RAX: 0000000000000087 RBX: 00005866a9e67ff8 RCX: 000000000000000a RDX: 0000000000000001 RSI: 0000000000000004 RDI: 0000000000000001 RBP: dffffc0000000000 R08: ffff88807c180003 R09: 1ffff1100f830000 R10: dffffc0000000000 R11: ffffed100f830001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000438 FS: 00007fe520225640(0000) GS:ffff8880b7e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005593c91b2c88 CR3: 000000014927c000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? __die_body+0x61/0xb0 ? die_addr+0xb1/0xe0 ? exc_general_protection+0x333/0x510 ? asm_exc_general_protection+0x26/0x30 ? jfs_ioc_trim+0x34b/0x8f0 jfs_ioctl+0x3c8/0x4f0 ? __pfx_jfs_ioctl+0x10/0x10 ? __pfx_jfs_ioctl+0x10/0x10 __se_sys_ioctl+0x269/0x350 ? __pfx___se_sys_ioctl+0x10/0x10 ? do_syscall_64+0xfb/0x210 do_syscall_64+0xee/0x210 ? syscall_exit_to_user_mode+0x1e0/0x330 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe51f4903ad Code: c3 e8 a7 2b 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d RSP: 002b:00007fe5202250c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe51f5cbf80 RCX: 00007fe51f4903ad RDX: 0000000020000680 RSI: 00000000c0185879 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe520225640 R13: 000000000000000e R14: 00007fe51f44fca0 R15: 00007fe52021d000 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:jfs_ioc_trim+0x34b/0x8f0 Code: e7 e8 59 a4 87 fe 4d 8b 24 24 4d 8d bc 24 38 04 00 00 48 8d 93 90 82 fe ff 4c 89 ff 31 f6 RSP: 0018:ffffc900055f7cd0 EFLAGS: 00010206 RAX: 0000000000000087 RBX: 00005866a9e67ff8 RCX: 000000000000000a RDX: 0000000000000001 RSI: 0000000000000004 RDI: 0000000000000001 RBP: dffffc0000000000 R08: ffff88807c180003 R09: 1ffff1100f830000 R10: dffffc0000000000 R11: ffffed100f830001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000438 FS: 00007fe520225640(0000) GS:ffff8880b7e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005593c91b2c88 CR3: 000000014927c000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Kernel panic - not syncing: Fatal exception [ Analysis ] We believe that we have found a concurrency bug in the `fs/jfs` module that results in a null pointer dereference. There is a closely related issue which has been fixed: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d6c1b3599b2feb5c7291f5ac3a36e5fa7cedb234 ... but, unfortunately, the accepted patch appears to still be susceptible to a null pointer dereference under some interleavings. To trigger the bug, we think that `JFS_SBI(ipbmap->i_sb)->bmap` is set to NULL in `dbFreeBits` and then dereferenced in `jfs_ioc_trim`. This bug manifests quite rarely under normal circumstances, but is triggereable from a syz-program. It has a CVSS v3.1 base score of 5.5 (MEDIUM).
How severe is CVE-2025-38203? +
CVE-2025-38203 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.
What products are affected by CVE-2025-38203? +
CVE-2025-38203 affects products from debian, linux, specifically: debian_linux, linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2025-38203? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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