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NVD / CVE Program· CNA Linux

CVE-2024-49903: jfs: Fix uaf in dbFreeBits

Noroxi assessment

Priority: Monitor (action score 28/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.25% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: Linux Linux 0c238da83f56bb895cab1e5851d034ac45b158d1, 3126ccde51f51b0648c8cdccaf916e8bd062e972, 4218b31ecc7af7e191768d32e32ed4386d8f9b76; azl3 kernel 6.6.51.1-5 on Azure Linux 3.0 6.6.57.1-2; azl3 kernel 6.6.57.1-2 on Azure Linux 3.0 6.6.57.1-2.

Low priority for now. Upgrade to Linux Linux 0c238da83f56bb895cab1e5851d034ac45b158d1, 3126ccde51f51b0648c8cdccaf916e8bd062e972, 4218b31ecc7af7e191768d32e32ed4386d8f9b76; azl3 kernel 6.6.51.1-5 on Azure Linux 3.0 6.6.57.1-2; azl3 kernel 6.6.57.1-2 on Azure Linux 3.0 6.6.57.1-2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: jfs: Fix uaf in dbFreeBits [syzbot reported] ================================================================== BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:587 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0xfe/0xd70 kernel/locking/mutex.c:752 Read of size 8 at addr ffff8880229254b0 by task syz-executor357/5216 CPU: 0 UID: 0 PID: 5216 Comm: syz-executor357 Not tainted 6.11.0-rc3-syzkaller-00156-gd7a5aa4b3c00 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 __mutex_lock_common kernel/locking/mutex.c:587 [inline] __mutex_lock+0xfe/0xd70 kernel/locking/mutex.c:752 dbFreeBits+0x7ea/0xd90 fs/jfs/jfs_dmap.c:2390 dbFreeDmap fs/jfs/jfs_dmap.c:2089 [inline] dbFree+0x35b/0x680 fs/jfs/jfs_dmap.c:409 dbDiscardAG+0x8a9/0xa20 fs/jfs/jfs_dmap.c:1650 jfs_ioc_trim+0x433/0x670 fs/jfs/jfs_discard.c:100 jfs_ioctl+0x2d0/0x3e0 fs/jfs/ioctl.c:131 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 Freed by task 5218: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2252 [inline] slab_free mm/slub.c:4473 [inline] kfree+0x149/0x360 mm/slub.c:4594 dbUnmount+0x11d/0x190 fs/jfs/jfs_dmap.c:278 jfs_mount_rw+0x4ac/0x6a0 fs/jfs/jfs_mount.c:247 jfs_remount+0x3d1/0x6b0 fs/jfs/super.c:454 reconfigure_super+0x445/0x880 fs/super.c:1083 vfs_cmd_reconfigure fs/fsopen.c:263 [inline] vfs_fsconfig_locked fs/fsopen.c:292 [inline] __do_sys_fsconfig fs/fsopen.c:473 [inline] __se_sys_fsconfig+0xb6e/0xf80 fs/fsopen.c:345 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f [Analysis] There are two paths (dbUnmount and jfs_ioc_trim) that generate race condition when accessing bmap, which leads to the occurrence of uaf. Use the lock s_umount to synchronize them, in order to avoid uaf caused by race condition.

HighCVSS 7.0 · v3.1—No exploit Fix available
Published
Oct 21, 2024
Updated
Oct 15, 2026
EPSS
0.2% · 17th percentile

Report tools

JSON

Action score

28

Monitor

Low priority for now.

CVSS
28 / 40 · 7.0 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2024-49903

When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernelbefore 5.10.227
  • linux linux kernel5.11 and later · before 5.15.168
  • linux linux kernel5.16 and later · before 6.1.113
  • linux linux kernel6.2 and later · before 6.6.55
  • linux linux kernel6.7 and later · before 6.10.14
  • linux linux kernel6.11 and later · before 6.11.3

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 3.7affected
    • b40c2e665cd552eae5fbdbb878bc29a34357668e and later · before 4ac58f7734937f3249da734ede946dfb3b1af5e4affected · git
    • b40c2e665cd552eae5fbdbb878bc29a34357668e and later · before 3126ccde51f51b0648c8cdccaf916e8bd062e972affected · git
    • b40c2e665cd552eae5fbdbb878bc29a34357668e and later · before fd026b6b6758d5569705c02540b40f3bbf822b9aaffected · git
    • b40c2e665cd552eae5fbdbb878bc29a34357668e and later · before e7ae14f7ee76c6ef5a48aebab1a278ad78f42619affected · git
    • b40c2e665cd552eae5fbdbb878bc29a34357668e and later · before 0c238da83f56bb895cab1e5851d034ac45b158d1affected · git
    • b40c2e665cd552eae5fbdbb878bc29a34357668e and later · before 4218b31ecc7af7e191768d32e32ed4386d8f9b76affected · git
    • b40c2e665cd552eae5fbdbb878bc29a34357668e and later · before a9603a6f75df2fd8125cd208c98cfaa0fe3f7505affected · git
    • b40c2e665cd552eae5fbdbb878bc29a34357668e and later · before 95accb7183badca387f7a8d19a2475cf3089f148affected · git
    • b40c2e665cd552eae5fbdbb878bc29a34357668e and later · before d6c1b3599b2feb5c7291f5ac3a36e5fa7cedb234affected · git

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.115-16.1.115-1
Debian:13linuxbefore 6.11.4-16.11.4-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2024-49901Oct 21, 2024 · drm/msm/adreno: Assign msm_gpu->pdev earlier to avoid nullptrs
    22Monitor
  • ← EarlierCVE-2024-49902Oct 21, 2024 · jfs: check if leafidx greater than num leaves per dmap tree
    22Monitor
  • Later →CVE-2024-49906Oct 21, 2024 · drm/amd/display: Check null pointer before try to access it
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux0c238da83f56bb895cab1e5851d034ac45b158d1Vendor (CNA)
Linux Linux3126ccde51f51b0648c8cdccaf916e8bd062e972Vendor (CNA)
Linux Linux4218b31ecc7af7e191768d32e32ed4386d8f9b76Vendor (CNA)
Linux Linux4ac58f7734937f3249da734ede946dfb3b1af5e4Vendor (CNA)
Linux Linux95accb7183badca387f7a8d19a2475cf3089f148Vendor (CNA)
Linux Linuxa9603a6f75df2fd8125cd208c98cfaa0fe3f7505Vendor (CNA)
Linux Linuxd6c1b3599b2feb5c7291f5ac3a36e5fa7cedb234Vendor (CNA)
Linux Linuxe7ae14f7ee76c6ef5a48aebab1a278ad78f42619Vendor (CNA)
Linux Linuxfd026b6b6758d5569705c02540b40f3bbf822b9aVendor (CNA)
azl3 kernel 6.6.51.1-5 on Azure Linux 3.06.6.57.1-2 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.57.1-2 on Azure Linux 3.06.6.57.1-2 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.167.1-2 on CBL Mariner 2.05.15.173.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.167.1-2 on CBL-Mariner 2.05.15.173.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.173.1-1 on CBL Mariner 2.05.15.173.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.115-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

c
free(dev->buf);/* ... another thread is still running ... */process(dev->buf);

Fixed

c
lock(&dev->lock);free(dev->buf);dev->buf = NULL;unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (12 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records